Yiisoft\Db\Pgsql\Schema

Complexity

Total Complexity

87

Size/Duplication

Total Lines	1023
Duplicated Lines	0 %

Test Coverage

Coverage

96.13%

Importance

Changes	3
Bugs	0	Features	0

22 Methods

Rating	Name	Duplication	Size	Complexity
B	findConstraints()	0	78	8
D	findColumns()	0	157	23
A	loadTableForeignKeys()	0	5	2
A	createColumnSchema()	0	3	1
B	loadColumnSchema()	0	50	8
A	loadTableUniques()	0	5	2
A	findUniqueIndexes()	0	26	6
B	loadTableConstraints()	0	119	8
A	getUniqueIndexInformation()	0	22	1
A	findSchemaNames()	0	10	1
A	resolveTableName()	0	23	3
A	loadTableIndexes()	0	56	2
A	createColumnSchemaBuilder()	0	3	1
A	loadTableSchema()	0	12	2
A	loadTableChecks()	0	5	2
A	resolveTableNames()	0	19	3
A	loadTablePrimaryKey()	0	5	2
A	loadTableDefaultValues()	0	3	1
A	createQueryBuilder()	0	3	1
A	findTableNames()	0	15	2
A	findViewNames()	0	15	2
A	insert()	0	27	6

<?php

declare(strict_types=1);

namespace Yiisoft\Db\Pgsql;

use JsonException;
use PDO;
use Throwable;
use Yiisoft\Arrays\ArrayHelper;
use Yiisoft\Db\Constraint\CheckConstraint;
use Yiisoft\Db\Constraint\Constraint;
use Yiisoft\Db\Constraint\ConstraintFinderInterface;
use Yiisoft\Db\Constraint\ConstraintFinderTrait;
use Yiisoft\Db\Constraint\DefaultValueConstraint;
use Yiisoft\Db\Constraint\ForeignKeyConstraint;
use Yiisoft\Db\Constraint\IndexConstraint;
use Yiisoft\Db\Exception\Exception;
use Yiisoft\Db\Exception\InvalidConfigException;
use Yiisoft\Db\Exception\NotSupportedException;
use Yiisoft\Db\Expression\Expression;
use Yiisoft\Db\Schema\ColumnSchemaBuilder;
use Yiisoft\Db\Schema\Schema as AbstractSchema;
use Yiisoft\Db\View\ViewFinderTrait;

use function array_change_key_case;
use function array_merge;
use function array_unique;
use function array_values;
use function bindec;
use function explode;
use function implode;
use function preg_match;
use function preg_replace;
use function str_replace;
use function substr;

/**
 * The class Schema is the class for retrieving metadata from a PostgreSQL database
 * (version 9.6 and above).
 *
 * @psalm-type ColumnArray = array{
 *   table_schema: string,
 *   table_name: string,
 *   column_name: string,
 *   data_type: string,
 *   type_type: string|null,
 *   character_maximum_length: int,
 *   column_comment: string|null,
 *   modifier: int,
 *   is_nullable: bool,
 *   column_default: mixed,
 *   is_autoinc: bool,
 *   sequence_name: string|null,
 *   enum_values: array<array-key, float|int|string>|string|null,
 *   numeric_precision: int|null,
 *   numeric_scale: int|null,
 *   size: string|null,
 *   is_pkey: bool|null,
 *   dimension: int
 * }
 *
 * @psalm-type ConstraintArray = array<
 *   array-key,
 *   array {
 *     name: string,
 *     column_name: string,
 *     type: string,
 *     foreign_table_schema: string|null,
 *     foreign_table_name: string|null,
 *     foreign_column_name: string|null,
 *     on_update: string,
 *     on_delete: string,
 *     check_expr: string
 *   }
 * >
 *
 * @psalm-type FindConstraintArray = array{
 *   constraint_name: string,
 *   column_name: string,
 *   foreign_table_name: string,
 *   foreign_table_schema: string,
 *   foreign_column_name: string,
 * }
 */
final class Schema extends AbstractSchema implements ConstraintFinderInterface
{
    use ConstraintFinderTrait;
    use ViewFinderTrait;

    public const TYPE_JSONB = 'jsonb';
    public const TYPE_INT_4_RANGE = 'int4range';
    public const TYPE_INT_8_RANGE = 'int8range';
    public const TYPE_NUM_RANGE = 'numrange';
    public const TYPE_TS_RANGE = 'tsrange';
    public const TYPE_TS_TZ_RANGE = 'tstzrange';
    public const TYPE_DATE_RANGE = 'daterange';

    /**
     * @var array<array-key, string> mapping from physical column types (keys) to abstract column types (values).

The doc comment array<array-key, string> at position 2 could not be parsed: Unknown type name 'array-key' at position 2 in array<array-key, string>.

     *
     * {@see http://www.postgresql.org/docs/current/static/datatype.html#DATATYPE-TABLE}
     */
    private array $typeMap = [
        'bit' => self::TYPE_INTEGER,
        'bit varying' => self::TYPE_INTEGER,
        'varbit' => self::TYPE_INTEGER,
        'bool' => self::TYPE_BOOLEAN,
        'boolean' => self::TYPE_BOOLEAN,
        'box' => self::TYPE_STRING,
        'circle' => self::TYPE_STRING,
        'point' => self::TYPE_STRING,
        'line' => self::TYPE_STRING,
        'lseg' => self::TYPE_STRING,
        'polygon' => self::TYPE_STRING,
        'path' => self::TYPE_STRING,
        'character' => self::TYPE_CHAR,
        'char' => self::TYPE_CHAR,
        'bpchar' => self::TYPE_CHAR,
        'character varying' => self::TYPE_STRING,
        'varchar' => self::TYPE_STRING,
        'text' => self::TYPE_TEXT,
        'bytea' => self::TYPE_BINARY,
        'cidr' => self::TYPE_STRING,
        'inet' => self::TYPE_STRING,
        'macaddr' => self::TYPE_STRING,
        'real' => self::TYPE_FLOAT,
        'float4' => self::TYPE_FLOAT,
        'double precision' => self::TYPE_DOUBLE,
        'float8' => self::TYPE_DOUBLE,
        'decimal' => self::TYPE_DECIMAL,
        'numeric' => self::TYPE_DECIMAL,
        'money' => self::TYPE_MONEY,
        'smallint' => self::TYPE_SMALLINT,
        'int2' => self::TYPE_SMALLINT,
        'int4' => self::TYPE_INTEGER,
        'int' => self::TYPE_INTEGER,
        'integer' => self::TYPE_INTEGER,
        'bigint' => self::TYPE_BIGINT,
        'int8' => self::TYPE_BIGINT,
        'oid' => self::TYPE_BIGINT, // should not be used. it's pg internal!
        'smallserial' => self::TYPE_SMALLINT,
        'serial2' => self::TYPE_SMALLINT,
        'serial4' => self::TYPE_INTEGER,
        'serial' => self::TYPE_INTEGER,
        'bigserial' => self::TYPE_BIGINT,
        'serial8' => self::TYPE_BIGINT,
        'pg_lsn' => self::TYPE_BIGINT,
        'date' => self::TYPE_DATE,
        'interval' => self::TYPE_STRING,
        'time without time zone' => self::TYPE_TIME,
        'time' => self::TYPE_TIME,
        'time with time zone' => self::TYPE_TIME,
        'timetz' => self::TYPE_TIME,
        'timestamp without time zone' => self::TYPE_TIMESTAMP,
        'timestamp' => self::TYPE_TIMESTAMP,
        'timestamp with time zone' => self::TYPE_TIMESTAMP,
        'timestamptz' => self::TYPE_TIMESTAMP,
        'abstime' => self::TYPE_TIMESTAMP,
        'tsquery' => self::TYPE_STRING,
        'tsvector' => self::TYPE_STRING,
        'txid_snapshot' => self::TYPE_STRING,
        'unknown' => self::TYPE_STRING,
        'uuid' => self::TYPE_STRING,
        'json' => self::TYPE_JSON,
        'jsonb' => self::TYPE_JSON,
        'xml' => self::TYPE_STRING,
        'int4range' => self::TYPE_INT_4_RANGE,
        'int8range' => self::TYPE_INT_8_RANGE,
        'numrange' => self::TYPE_NUM_RANGE,
        'tsrange' => self::TYPE_TS_RANGE,
        'tstzrange' => self::TYPE_TS_TZ_RANGE,
        'daterange' => self::TYPE_DATE_RANGE,
    ];

    /**
     * @var string|null the default schema used for the current session.
     */
    protected ?string $defaultSchema = 'public';

    /**
     * @var string|string[] character used to quote schema, table, etc. names. An array of 2 characters can be used in
     * case starting and ending characters are different.
     */
    protected $tableQuoteCharacter = '"';

    /**
     * Resolves the table name and schema name (if any).
     *
     * @param string $name the table name.
     *
     * @return TableSchema with resolved table, schema, etc. names.
     *
     * {@see TableSchema}
     */
    protected function resolveTableName(string $name): TableSchema
    {
        $resolvedName = new TableSchema();

        $parts = explode('.', str_replace('"', '', $name));

        if (isset($parts[1])) {
            $resolvedName->schemaName($parts[0]);
            $resolvedName->name($parts[1]);
        } else {
            $resolvedName->schemaName($this->defaultSchema);
            $resolvedName->name($name);
        }

        $resolvedName->fullName(
            (
                $resolvedName->getSchemaName() !== $this->defaultSchema ?
                    (string) $resolvedName->getSchemaName() . '.' :
                    ''
            ) . $resolvedName->getName()
        );

        return $resolvedName;
    }

    /**
     * Returns all schema names in the database, including the default one but not system schemas.
     *
     * This method should be overridden by child classes in order to support this feature because the default
     * implementation simply throws an exception.
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return array all schema names in the database, except system schemas.
     */
    protected function findSchemaNames(): array
    {
        $sql = <<<'SQL'
            SELECT "ns"."nspname"
            FROM "pg_namespace" AS "ns"
            WHERE "ns"."nspname" != 'information_schema' AND "ns"."nspname" NOT LIKE 'pg_%'
            ORDER BY "ns"."nspname" ASC
            SQL;

        return $this->getDb()->createCommand($sql)->queryColumn();
    }

    /**
     * Returns all table names in the database.
     *
     * This method should be overridden by child classes in order to support this feature because the default
     * implementation simply throws an exception.
     *
     * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return array all table names in the database. The names have NO schema name prefix.
     */
    protected function findTableNames(string $schema = ''): array
    {
        if ($schema === '') {
            $schema = $this->defaultSchema;
        }

        $sql = <<<'SQL'
            SELECT c.relname AS table_name
            FROM pg_class c
            INNER JOIN pg_namespace ns ON ns.oid = c.relnamespace
            WHERE ns.nspname = :schemaName AND c.relkind IN ('r','v','m','f', 'p')
            ORDER BY c.relname
            SQL;

        return $this->getDb()->createCommand($sql, [':schemaName' => $schema])->queryColumn();
    }

    /**
     * Loads the metadata for the specified table.
     *
     * @param string $name table name.
     *
     * @throws Exception|InvalidConfigException
     *
     * @return TableSchema|null DBMS-dependent table metadata, `null` if the table does not exist.
     */
    protected function loadTableSchema(string $name): ?TableSchema
    {
        $table = new TableSchema();

        $this->resolveTableNames($table, $name);

        if ($this->findColumns($table)) {
            $this->findConstraints($table);
            return $table;
        }

        return null;
    }

    /**
     * Loads a primary key for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws Exception|InvalidConfigException
     *
     * @return Constraint|null primary key for the given table, `null` if the table has no primary key.
     */
    protected function loadTablePrimaryKey(string $tableName): ?Constraint
    {
        $tablePrimaryKey = $this->loadTableConstraints($tableName, 'primaryKey');

        return $tablePrimaryKey instanceof Constraint ? $tablePrimaryKey : null;
    }

    /**
     * Loads all foreign keys for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws Exception|InvalidConfigException
     *
     * @return array|ForeignKeyConstraint[] foreign keys for the given table.
     */
    protected function loadTableForeignKeys(string $tableName): array
    {
        $tableForeignKeys = $this->loadTableConstraints($tableName, 'foreignKeys');

        return is_array($tableForeignKeys) ? $tableForeignKeys : [];
    }

    /**
     * Loads all indexes for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return IndexConstraint[] indexes for the given table.
     */
    protected function loadTableIndexes(string $tableName): array
    {
        $sql = <<<'SQL'
            SELECT
                "ic"."relname" AS "name",
                "ia"."attname" AS "column_name",
                "i"."indisunique" AS "index_is_unique",
                "i"."indisprimary" AS "index_is_primary"
            FROM "pg_class" AS "tc"
            INNER JOIN "pg_namespace" AS "tcns"
                ON "tcns"."oid" = "tc"."relnamespace"
            INNER JOIN "pg_index" AS "i"
                ON "i"."indrelid" = "tc"."oid"
            INNER JOIN "pg_class" AS "ic"
                ON "ic"."oid" = "i"."indexrelid"
            INNER JOIN "pg_attribute" AS "ia"
                ON "ia"."attrelid" = "i"."indexrelid"
            WHERE "tcns"."nspname" = :schemaName AND "tc"."relname" = :tableName
            ORDER BY "ia"."attnum" ASC
            SQL;

        $resolvedName = $this->resolveTableName($tableName);

        $indexes = $this->getDb()->createCommand($sql, [
            ':schemaName' => $resolvedName->getSchemaName(),
            ':tableName' => $resolvedName->getName(),
        ])->queryAll();

        /** @var array<array-key, array<array-key, mixed>> @indexes */
        $indexes = $this->normalizePdoRowKeyCase($indexes, true);
        $indexes = ArrayHelper::index($indexes, null, 'name');
        $result = [];

        /**
         * @var object|string|null $name
         * @var array<
         *   array-key,
         *   array{
         *     name: string,
         *     column_name: string,
         *     index_is_unique: bool,
         *     index_is_primary: bool
         *   }
         * > $index
         */
        foreach ($indexes as $name => $index) {
            $ic = (new IndexConstraint())
                ->name($name)
                ->columnNames(ArrayHelper::getColumn($index, 'column_name'))
                ->primary($index[0]['index_is_primary'])
                ->unique($index[0]['index_is_unique']);

            $result[] = $ic;
        }

        return $result;
    }

    /**
     * Loads all unique constraints for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws Exception|InvalidConfigException
     *
     * @return array|Constraint[] unique constraints for the given table.
     */
    protected function loadTableUniques(string $tableName): array
    {
        $tableUniques = $this->loadTableConstraints($tableName, 'uniques');

        return is_array($tableUniques) ? $tableUniques : [];
    }

    /**
     * Loads all check constraints for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws Exception|InvalidConfigException
     *
     * @return array|CheckConstraint[] check constraints for the given table.
     */
    protected function loadTableChecks(string $tableName): array
    {
        $tableChecks = $this->loadTableConstraints($tableName, 'checks');

        return is_array($tableChecks) ? $tableChecks : [];
    }

    /**
     * Loads all default value constraints for the given table.
     *
     * @param string $tableName table name.
     *
     * @throws NotSupportedException
     *
     * @return DefaultValueConstraint[] default value constraints for the given table.
     */
    protected function loadTableDefaultValues(string $tableName): array

The parameter $tableName is not used and could be removed.

    {
        throw new NotSupportedException('PostgreSQL does not support default value constraints.');
    }

    /**
     * Creates a query builder for the PostgreSQL database.
     *
     * @return QueryBuilder query builder instance
     */
    public function createQueryBuilder(): QueryBuilder
    {
        return new QueryBuilder($this->getDb());
    }

    /**
     * Resolves the table name and schema name (if any).
     *
     * @param TableSchema $table the table metadata object.
     * @param string $name the table name
     */
    protected function resolveTableNames(TableSchema $table, string $name): void
    {
        $parts = explode('.', str_replace('"', '', $name));

        if (isset($parts[1])) {
            $table->schemaName($parts[0]);
            $table->name($parts[1]);
        } else {
            $table->schemaName($this->defaultSchema);
            $table->name($parts[0]);
        }

        if ($table->getSchemaName() !== $this->defaultSchema) {
            $name = (string) $table->getSchemaName() . '.' . $table->getName();
        } else {
            $name = $table->getName();
        }

        $table->fullName($name);
    }

    protected function findViewNames(string $schema = ''): array
    {
        if ($schema === '') {
            $schema = $this->defaultSchema;
        }

        $sql = <<<'SQL'
            SELECT c.relname AS table_name
            FROM pg_class c
            INNER JOIN pg_namespace ns ON ns.oid = c.relnamespace
            WHERE ns.nspname = :schemaName AND (c.relkind = 'v' OR c.relkind = 'm')
            ORDER BY c.relname
            SQL;

        return $this->getDb()->createCommand($sql, [':schemaName' => $schema])->queryColumn();
    }

    /**
     * Collects the foreign key column details for the given table.
     *
     * @param TableSchema $table the table metadata
     *
     * @throws Exception|InvalidConfigException|Throwable
     */
    protected function findConstraints(TableSchema $table): void
    {
        $tableName = $table->getName();
        $tableSchema = $table->getSchemaName();

        $tableName = $this->quoteValue($tableName);

        if ($tableSchema !== null) {
            $tableSchema = $this->quoteValue($tableSchema);
        }

        /**
         * We need to extract the constraints de hard way since:
         * {@see http://www.postgresql.org/message-id/26677.1086673982@sss.pgh.pa.us}
         */

        $sql = <<<SQL
            SELECT
                ct.conname as constraint_name,
                a.attname as column_name,
                fc.relname as foreign_table_name,
                fns.nspname as foreign_table_schema,
                fa.attname as foreign_column_name
            FROM
                (SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype, ct.confkey,
                        generate_subscripts(ct.conkey, 1) AS s
                   FROM pg_constraint ct
                ) AS ct
                inner join pg_class c on c.oid=ct.conrelid
                inner join pg_namespace ns on c.relnamespace=ns.oid
                inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum = ct.conkey[ct.s]
                left join pg_class fc on fc.oid=ct.confrelid
                left join pg_namespace fns on fc.relnamespace=fns.oid
                left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum = ct.confkey[ct.s]
            WHERE
                ct.contype='f'
                and c.relname={$tableName}
                and ns.nspname={$tableSchema}
            ORDER BY
                fns.nspname, fc.relname, a.attnum
            SQL;

        /** @var array{array{tableName: string, columns: array}} $constraints */
        $constraints = [];
        $slavePdo = $this->getDb()->getSlavePdo();

        /** @var FindConstraintArray $constraint */
        foreach ($this->getDb()->createCommand($sql)->queryAll() as $constraint) {
            if ($slavePdo !== null && $slavePdo->getAttribute(PDO::ATTR_CASE) === PDO::CASE_UPPER) {
                $constraint = array_change_key_case($constraint, CASE_LOWER);
            }

            if ($constraint['foreign_table_schema'] !== $this->defaultSchema) {
                $foreignTable = $constraint['foreign_table_schema'] . '.' . $constraint['foreign_table_name'];
            } else {
                $foreignTable = $constraint['foreign_table_name'];
            }

            $name = $constraint['constraint_name'];

            if (!isset($constraints[$name])) {
                $constraints[$name] = [
                    'tableName' => $foreignTable,
                    'columns' => [],
                ];
            }

            $constraints[$name]['columns'][$constraint['column_name']] = $constraint['foreign_column_name'];
        }

        /**
         * @var int|string $foreingKeyName.
         * @var array{tableName: string, columns: array} $constraint
         */
        foreach ($constraints as $foreingKeyName => $constraint) {
            $table->foreignKey(
                (string) $foreingKeyName,
                array_merge([$constraint['tableName']], $constraint['columns'])
            );
        }
    }

    /**
     * Gets information about given table unique indexes.
     *
     * @param TableSchema $table the table metadata.
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return array with index and column names.
     */
    protected function getUniqueIndexInformation(TableSchema $table): array
    {
        $sql = <<<'SQL'
            SELECT
                i.relname as indexname,
                pg_get_indexdef(idx.indexrelid, k + 1, TRUE) AS columnname
            FROM (
              SELECT *, generate_subscripts(indkey, 1) AS k
              FROM pg_index
            ) idx
            INNER JOIN pg_class i ON i.oid = idx.indexrelid
            INNER JOIN pg_class c ON c.oid = idx.indrelid
            INNER JOIN pg_namespace ns ON c.relnamespace = ns.oid
            WHERE idx.indisprimary = FALSE AND idx.indisunique = TRUE
            AND c.relname = :tableName AND ns.nspname = :schemaName
            ORDER BY i.relname, k
            SQL;

        return $this->getDb()->createCommand($sql, [
            ':schemaName' => $table->getSchemaName(),
            ':tableName' => $table->getName(),
        ])->queryAll();
    }

    /**
     * Returns all unique indexes for the given table.
     *
     * Each array element is of the following structure:
     *
     * ```php
     * [
     *     'IndexName1' => ['col1' [, ...]],
     *     'IndexName2' => ['col2' [, ...]],
     * ]
     * ```
     *
     * @param TableSchema $table the table metadata
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return array all unique indexes for the given table.
     */
    public function findUniqueIndexes(TableSchema $table): array
    {
        $uniqueIndexes = [];
        $slavePdo = $this->getDb()->getSlavePdo();

        /** @var array{indexname: string, columnname: string} $row */
        foreach ($this->getUniqueIndexInformation($table) as $row) {
            if ($slavePdo !== null && $slavePdo->getAttribute(PDO::ATTR_CASE) === PDO::CASE_UPPER) {
                $row = array_change_key_case($row, CASE_LOWER);
            }

            $column = $row['columnname'];

            if (!empty($column) && $column[0] === '"') {
                /**
                 * postgres will quote names that are not lowercase-only.
                 *
                 * {@see https://github.com/yiisoft/yii2/issues/10613}
                 */
                $column = substr($column, 1, -1);
            }

            $uniqueIndexes[$row['indexname']][] = $column;
        }

        return $uniqueIndexes;
    }

    /**
     * Collects the metadata of table columns.
     *
     * @param TableSchema $table the table metadata.
     *
     * @throws Exception|InvalidConfigException|JsonException|Throwable
     *
     * @return bool whether the table exists in the database.
     */
    protected function findColumns(TableSchema $table): bool
    {
        $tableName = $table->getName();
        $schemaName = $table->getSchemaName();
        $orIdentity = '';

        $tableName = $this->getDb()->quoteValue($tableName);

        if ($schemaName !== null) {
            $schemaName = $this->getDb()->quoteValue($schemaName);
        }

        if (version_compare($this->getDb()->getServerVersion(), '12.0', '>=')) {
            $orIdentity = 'OR a.attidentity != \'\'';
        }

        $sql = <<<SQL
            SELECT
                d.nspname AS table_schema,
                c.relname AS table_name,
                a.attname AS column_name,
                COALESCE(td.typname, tb.typname, t.typname) AS data_type,
                COALESCE(td.typtype, tb.typtype, t.typtype) AS type_type,
                a.attlen AS character_maximum_length,
                pg_catalog.col_description(c.oid, a.attnum) AS column_comment,
                a.atttypmod AS modifier,
                a.attnotnull = false AS is_nullable,
                CAST(pg_get_expr(ad.adbin, ad.adrelid) AS varchar) AS column_default,
                coalesce(pg_get_expr(ad.adbin, ad.adrelid) ~ 'nextval',false) {$orIdentity} AS is_autoinc,
                pg_get_serial_sequence(quote_ident(d.nspname) || '.' || quote_ident(c.relname), a.attname)
                    AS sequence_name,
                CASE WHEN COALESCE(td.typtype, tb.typtype, t.typtype) = 'e'::char
                    THEN array_to_string(
                        (
                            SELECT array_agg(enumlabel)
                            FROM pg_enum
                            WHERE enumtypid = COALESCE(td.oid, tb.oid, a.atttypid)
                            )::varchar[],
                        ',')
                    ELSE NULL
                END AS enum_values,
                CASE atttypid
                     WHEN 21 /*int2*/ THEN 16
                     WHEN 23 /*int4*/ THEN 32
                     WHEN 20 /*int8*/ THEN 64
                     WHEN 1700 /*numeric*/ THEN
                          CASE WHEN atttypmod = -1
                           THEN null
                           ELSE ((atttypmod - 4) >> 16) & 65535
                           END
                     WHEN 700 /*float4*/ THEN 24 /*FLT_MANT_DIG*/
                     WHEN 701 /*float8*/ THEN 53 /*DBL_MANT_DIG*/
                     ELSE null
                  END   AS numeric_precision,
                  CASE
                    WHEN atttypid IN (21, 23, 20) THEN 0
                    WHEN atttypid IN (1700) THEN
                    CASE
                        WHEN atttypmod = -1 THEN null
                        ELSE (atttypmod - 4) & 65535
                    END
                       ELSE null
                  END AS numeric_scale,
                CAST(
                         information_schema._pg_char_max_length(
                             information_schema._pg_truetypid(a, t),
                             information_schema._pg_truetypmod(a, t)
                             ) AS numeric
                ) AS size,
                a.attnum = any (ct.conkey) as is_pkey,
                COALESCE(NULLIF(a.attndims, 0), NULLIF(t.typndims, 0), (t.typcategory='A')::int) AS dimension
            FROM
                pg_class c
                LEFT JOIN pg_attribute a ON a.attrelid = c.oid
                LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
                LEFT JOIN pg_type t ON a.atttypid = t.oid
                LEFT JOIN pg_type tb ON (a.attndims > 0 OR t.typcategory='A') AND t.typelem > 0 AND t.typelem = tb.oid
                                            OR t.typbasetype > 0 AND t.typbasetype = tb.oid
                LEFT JOIN pg_type td ON t.typndims > 0 AND t.typbasetype > 0 AND tb.typelem = td.oid
                LEFT JOIN pg_namespace d ON d.oid = c.relnamespace
                LEFT JOIN pg_constraint ct ON ct.conrelid = c.oid AND ct.contype = 'p'
            WHERE
                a.attnum > 0 AND t.typname != '' AND NOT a.attisdropped
                AND c.relname = {$tableName}
                AND d.nspname = {$schemaName}
            ORDER BY
                a.attnum;
            SQL;

        /** @var array columns */
        $columns = $this->getDb()->createCommand($sql)->queryAll();
        $slavePdo = $this->getDb()->getSlavePdo();

        if (empty($columns)) {
            return false;
        }

        /** @var array<array-key, mixed> $column */
        foreach ($columns as $column) {
            if ($slavePdo !== null && $slavePdo->getAttribute(PDO::ATTR_CASE) === PDO::CASE_UPPER) {
                $column = array_change_key_case($column, CASE_LOWER);
            }

            /** @psalm-var ColumnArray $column */
            $loadColumnSchema = $this->loadColumnSchema($column);
            $table->columns($loadColumnSchema->getName(), $loadColumnSchema);

            /** @var mixed $defaultValue */
            $defaultValue = $loadColumnSchema->getDefaultValue();

            if ($loadColumnSchema->isPrimaryKey()) {
                $table->primaryKey($loadColumnSchema->getName());

                if ($table->getSequenceName() === null) {
                    $table->sequenceName($loadColumnSchema->getSequenceName());
                }

                $loadColumnSchema->defaultValue(null);
            } elseif ($defaultValue) {
                if (
                    is_string($defaultValue) &&
                    in_array(
                        $loadColumnSchema->getType(),
                        [self::TYPE_TIMESTAMP, self::TYPE_DATE, self::TYPE_TIME],
                        true
                    ) &&
                    in_array(
                        strtoupper($defaultValue),
                        ['NOW()', 'CURRENT_TIMESTAMP', 'CURRENT_DATE', 'CURRENT_TIME'],
                        true
                    )
                ) {
                    $loadColumnSchema->defaultValue(new Expression($defaultValue));
                } elseif ($loadColumnSchema->getType() === 'boolean') {
                    $loadColumnSchema->defaultValue(($defaultValue  === 'true'));
                } elseif (is_string($defaultValue) && preg_match("/^B'(.*?)'::/", $defaultValue, $matches)) {
                    $loadColumnSchema->defaultValue(bindec($matches[1]));
                } elseif (is_string($defaultValue) && preg_match("/^'(\d+)'::\"bit\"$/", $defaultValue, $matches)) {
                    $loadColumnSchema->defaultValue(bindec($matches[1]));
                } elseif (is_string($defaultValue) && preg_match("/^'(.*?)'::/", $defaultValue, $matches)) {
                    $loadColumnSchema->defaultValue($loadColumnSchema->phpTypecast($matches[1]));
                } elseif (
                    is_string($defaultValue) &&
                    preg_match('/^(\()?(.*?)(?(1)\))(?:::.+)?$/', $defaultValue, $matches)
                ) {
                    if ($matches[2] === 'NULL') {
                        $loadColumnSchema->defaultValue(null);
                    } else {
                        $loadColumnSchema->defaultValue($loadColumnSchema->phpTypecast($matches[2]));
                    }
                } else {
                    $loadColumnSchema->defaultValue($loadColumnSchema->phpTypecast($defaultValue));
                }
            }
        }

        return true;
    }

    /**
     * Loads the column information into a {@see ColumnSchema} object.
     *
     * @param array{
     *   table_schema: string,
     *   table_name: string,
     *   column_name: string,
     *   data_type: string,
     *   type_type: string|null,
     *   character_maximum_length: int,
     *   column_comment: string|null,
     *   modifier: int,
     *   is_nullable: bool,
     *   column_default: mixed,
     *   is_autoinc: bool,
     *   sequence_name: string|null,
     *   enum_values: array<array-key, float|int|string>|string|null,
     *   numeric_precision: int|null,
     *   numeric_scale: int|null,
     *   size: string|null,
     *   is_pkey: bool|null,
     *   dimension: int
     * } $info column information.
     *
     * @return ColumnSchema the column schema object.
     */
    protected function loadColumnSchema(array $info): ColumnSchema
    {
        $column = $this->createColumnSchema();
        $column->allowNull($info['is_nullable']);
        $column->autoIncrement($info['is_autoinc']);
        $column->comment($info['column_comment']);
        $column->dbType($info['data_type']);
        $column->defaultValue($info['column_default']);
        $column->enumValues(($info['enum_values'] !== null)
            ? explode(',', str_replace(["''"], ["'"], $info['enum_values'])) : null);
        $column->unsigned(false); // has no meaning in PG
        $column->primaryKey((bool) $info['is_pkey']);
        $column->name($info['column_name']);
        $column->precision($info['numeric_precision']);
        $column->scale($info['numeric_scale']);
        $column->size($info['size'] === null ? null : (int) $info['size']);
        $column->dimension($info['dimension']);

        /**
         * pg_get_serial_sequence() doesn't track DEFAULT value change. GENERATED BY IDENTITY columns always have null
         * default value.
         *
         * @var mixed $defaultValue
         */
        $defaultValue = $column->getDefaultValue();
        $sequenceName = $info['sequence_name'] ?? null;

        if (
            isset($defaultValue) &&
            is_string($defaultValue) &&
            preg_match("/nextval\\('\"?\\w+\"?\.?\"?\\w+\"?'(::regclass)?\\)/", $defaultValue) === 1
        ) {
            $column->sequenceName(preg_replace(
                ['/nextval/', '/::/', '/regclass/', '/\'\)/', '/\(\'/'],
                '',
                $defaultValue
            ));
        } elseif ($sequenceName !== null) {
            $column->sequenceName($this->resolveTableName($sequenceName)->getFullName());
        }

        if (isset($this->typeMap[$column->getDbType()])) {
            $column->type($this->typeMap[$column->getDbType()]);
        } else {
            $column->type(self::TYPE_STRING);
        }

        $column->phpType($this->getColumnPhpType($column));

        return $column;
    }

    /**
     * Executes the INSERT command, returning primary key values.
     *
     * @param string $table the table that new rows will be inserted into.
     * @param array $columns the column data (name => value) to be inserted into the table.
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return array|false primary key values or false if the command fails.
     */
    public function insert(string $table, array $columns)
    {
        $params = [];
        $returnColumns = [];
        $sql = $this->getDb()->getQueryBuilder()->insert($table, $columns, $params);
        $tableSchema = $this->getTableSchema($table);

        if ($tableSchema !== null) {
            $returnColumns = $tableSchema->getPrimaryKey();
        }

        if (!empty($returnColumns)) {
            $returning = [];
            /** @var string $name */
            foreach ($returnColumns as $name) {
                $returning[] = $this->quoteColumnName($name);
            }
            $sql .= ' RETURNING ' . implode(', ', $returning);
        }

        $command = $this->getDb()->createCommand($sql, $params);
        $command->prepare(false);
        $result = $command->queryOne();

        $pdoStatement = $command->getPdoStatement();

        return $pdoStatement !== null && !$pdoStatement->rowCount() ? false : $result;
    }

    /**
     * Loads multiple types of constraints and returns the specified ones.
     *
     * @param string $tableName table name.
     * @param string $returnType return type:
     * - primaryKey
     * - foreignKeys
     * - uniques
     * - checks
     *
     * @throws Exception|InvalidConfigException|Throwable
     *
     * @return (CheckConstraint|Constraint|ForeignKeyConstraint)[]|Constraint|null constraints.
     *
     * @psalm-return Constraint|list<CheckConstraint|Constraint|ForeignKeyConstraint>|null
     */
    private function loadTableConstraints(string $tableName, string $returnType)
    {
        /** @var string $sql */
        $sql = <<<'SQL'
            SELECT
                "c"."conname" AS "name",
                "a"."attname" AS "column_name",
                "c"."contype" AS "type",
                "ftcns"."nspname" AS "foreign_table_schema",
                "ftc"."relname" AS "foreign_table_name",
                "fa"."attname" AS "foreign_column_name",
                "c"."confupdtype" AS "on_update",
                "c"."confdeltype" AS "on_delete",
                pg_get_constraintdef("c"."oid") AS "check_expr"
            FROM "pg_class" AS "tc"
            INNER JOIN "pg_namespace" AS "tcns"
                ON "tcns"."oid" = "tc"."relnamespace"
            INNER JOIN "pg_constraint" AS "c"
                ON "c"."conrelid" = "tc"."oid"
            INNER JOIN "pg_attribute" AS "a"
                ON "a"."attrelid" = "c"."conrelid" AND "a"."attnum" = ANY ("c"."conkey")
            LEFT JOIN "pg_class" AS "ftc"
                ON "ftc"."oid" = "c"."confrelid"
            LEFT JOIN "pg_namespace" AS "ftcns"
                ON "ftcns"."oid" = "ftc"."relnamespace"
            LEFT JOIN "pg_attribute" "fa"
                ON "fa"."attrelid" = "c"."confrelid" AND "fa"."attnum" = ANY ("c"."confkey")
            WHERE "tcns"."nspname" = :schemaName AND "tc"."relname" = :tableName
            ORDER BY "a"."attnum" ASC, "fa"."attnum" ASC
            SQL;

        /** @var array<array-key, string> $actionTypes */
        $actionTypes = [
            'a' => 'NO ACTION',
            'r' => 'RESTRICT',
            'c' => 'CASCADE',
            'n' => 'SET NULL',
            'd' => 'SET DEFAULT',
        ];

        $resolvedName = $this->resolveTableName($tableName);

        $constraints = $this->getDb()->createCommand($sql, [
            ':schemaName' => $resolvedName->getSchemaName(),
            ':tableName' => $resolvedName->getName(),
        ])->queryAll();

        /** @var array<array-key, array> $constraints */
        $constraints = $this->normalizePdoRowKeyCase($constraints, true);
        $constraints = ArrayHelper::index($constraints, null, ['type', 'name']);

        $result = [
            'primaryKey' => null,
            'foreignKeys' => [],
            'uniques' => [],
            'checks' => [],
        ];

        /**
         * @var string $type
         * @var array $names
         */
        foreach ($constraints as $type => $names) {
            /**
             * @psalm-var object|string|null $name
             * @psalm-var ConstraintArray $constraint
             */
            foreach ($names as $name => $constraint) {
                switch ($type) {
                    case 'p':
                        $ct = (new Constraint())
                            ->name($name)
                            ->columnNames(ArrayHelper::getColumn($constraint, 'column_name'));

                        $result['primaryKey'] = $ct;
                        break;
                    case 'f':
                        $onDelete = $actionTypes[$constraint[0]['on_delete']] ?? null;
                        $onUpdate = $actionTypes[$constraint[0]['on_update']] ?? null;

                        $fk = (new ForeignKeyConstraint())
                            ->name($name)
                            ->columnNames(array_values(
                                array_unique(ArrayHelper::getColumn($constraint, 'column_name'))
                            ))
                            ->foreignSchemaName($constraint[0]['foreign_table_schema'])
                            ->foreignTableName($constraint[0]['foreign_table_name'])
                            ->foreignColumnNames(array_values(
                                array_unique(ArrayHelper::getColumn($constraint, 'foreign_column_name'))
                            ))
                            ->onDelete($onDelete)
                            ->onUpdate($onUpdate);

                        $result['foreignKeys'][] = $fk;
                        break;
                    case 'u':
                        $ct = (new Constraint())
                            ->name($name)
                            ->columnNames(ArrayHelper::getColumn($constraint, 'column_name'));

                        $result['uniques'][] = $ct;
                        break;
                    case 'c':
                        $ck = (new CheckConstraint())
                            ->name($name)
                            ->columnNames(ArrayHelper::getColumn($constraint, 'column_name'))
                            ->expression($constraint[0]['check_expr']);

                        $result['checks'][] = $ck;
                        break;
                }
            }
        }

        foreach ($result as $type => $data) {
            $this->setTableMetadata($tableName, $type, $data);
        }

        return $result[$returnType];
    }

    /**
     * Creates a column schema for the database.
     *
     * This method may be overridden by child classes to create a DBMS-specific column schema.
     *
     * @return ColumnSchema column schema instance.
     */
    private function createColumnSchema(): ColumnSchema
    {
        return new ColumnSchema();
    }

    /**
     * Create a column schema builder instance giving the type and value precision.
     *
     * This method may be overridden by child classes to create a DBMS-specific column schema builder.
     *
     * @param string $type type of the column. See {@see ColumnSchemaBuilder::$type}.
     * @param array|int|string|null $length length or precision of the column. See {@see ColumnSchemaBuilder::$length}.
     *
     * @return ColumnSchemaBuilder column schema builder instance
     */
    public function createColumnSchemaBuilder(string $type, $length = null): ColumnSchemaBuilder
    {
        return new ColumnSchemaBuilder($type, $length);
    }
}