Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like SQLDataSet often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use SQLDataSet, and based on these observations, apply Extract Interface, too.
1 | <?php |
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4 | class SQLDataSet extends DataSet |
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5 | { |
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6 | protected $pdo; |
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7 | |||
8 | public function __construct($params) |
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9 | { |
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10 | if(isset($params['user'])) |
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11 | { |
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12 | $this->pdo = new \PDO($params['dsn'], $params['user'], $params['pass']); |
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13 | } |
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14 | else |
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15 | { |
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16 | $this->pdo = new \PDO($params['dsn']); |
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17 | } |
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18 | } |
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19 | |||
20 | /** |
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21 | * Get the number of rows affected by the query |
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22 | * |
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23 | * @param string $sql The SQL string |
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24 | * |
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25 | * @return integer The number of rows affected by the query |
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26 | */ |
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27 | private function _get_row_count_for_query($sql) |
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28 | { |
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29 | $stmt = $this->pdo->query($sql); |
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30 | if($stmt === false) |
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31 | { |
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32 | return 0; |
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33 | } |
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34 | $count = $stmt->rowCount(); |
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35 | if($count === 0) |
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36 | { |
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37 | $array = $stmt->fetchAll(); |
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38 | $count = count($array); |
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39 | } |
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40 | return $count; |
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41 | } |
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42 | |||
43 | function _tableExistsNoPrefix($name) |
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44 | { |
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45 | if($this->_get_row_count_for_query('SHOW TABLES LIKE '.$this->pdo->quote($name)) > 0) |
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46 | { |
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47 | return true; |
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48 | } |
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49 | else if($this->_get_row_count_for_query('SELECT * FROM sqlite_master WHERE name LIKE '.$this->pdo->quote($name)) > 0) |
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50 | { |
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51 | return true; |
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52 | } |
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53 | return false; |
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54 | } |
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55 | |||
56 | function _tableExists($name) |
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57 | { |
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58 | if($this->_get_row_count_for_query('SHOW TABLES LIKE '.$this->pdo->quote('tbl'.$name)) > 0) |
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59 | { |
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60 | return true; |
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61 | } |
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62 | else if($this->_get_row_count_for_query('SELECT * FROM sqlite_master WHERE name LIKE '.$this->pdo->quote('tbl'.$name)) > 0) |
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63 | { |
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64 | return true; |
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65 | } |
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66 | return false; |
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67 | } |
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68 | |||
69 | function _viewExists($name) |
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70 | { |
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71 | if($this->_get_row_count_for_query('SHOW TABLES LIKE '.$this->pdo->quote('v'.$name)) > 0) |
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72 | { |
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73 | return true; |
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74 | } |
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75 | else if($this->_get_row_count_for_query('SELECT * FROM sqlite_master WHERE name LIKE '.$this->pdo->quote('v'.$name)) > 0) |
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76 | { |
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77 | return true; |
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78 | } |
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79 | return false; |
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80 | } |
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81 | |||
82 | function tableExists($name) |
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83 | { |
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84 | if($this->_tableExists($name)) |
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85 | { |
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86 | return true; |
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87 | } |
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88 | if($this->_tableExistsNoPrefix($name)) |
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89 | { |
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90 | return true; |
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91 | } |
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92 | if($this->_viewExists($name)) |
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93 | { |
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94 | return true; |
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95 | } |
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96 | return false; |
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97 | } |
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98 | |||
99 | function getTable($name) |
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100 | { |
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101 | if($this->_tableExists($name)) |
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102 | { |
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103 | return new SQLDataTable($this, 'tbl'.$name); |
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104 | } |
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105 | if($this->_viewExists($name)) |
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106 | { |
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107 | return new SQLDataTable($this, 'v'.$name); |
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108 | } |
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109 | if($this->_tableExistsNoPrefix($name)) |
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110 | { |
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111 | return new SQLDataTable($this, $name); |
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112 | } |
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113 | throw new \Exception('No such table '.$name); |
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114 | } |
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115 | |||
116 | /** |
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117 | * @param array $sort The array to sort by or false to not sort |
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118 | */ |
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119 | private function getOrderByClause($sort) |
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120 | { |
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121 | if(empty($sort)) |
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122 | { |
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123 | return false; |
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124 | } |
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125 | $sql = ' ORDER BY '; |
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126 | $tmp = array(); |
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127 | foreach($sort as $sort_col=>$dir) |
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128 | { |
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129 | array_push($tmp, $sort_col.' '.($dir === 1 ? 'ASC' : 'DESC')); |
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130 | } |
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131 | $sql .= implode($tmp, ','); |
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132 | return $sql; |
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133 | } |
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134 | |||
135 | private function getLimitClause($count, $skip) |
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136 | { |
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137 | if($count === false) |
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138 | { |
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139 | return false; |
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140 | } |
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141 | $count = intval($count); |
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142 | if($skip !== false) |
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143 | { |
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144 | $skip = intval($count); |
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145 | return " LIMIT $skip, $count"; |
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146 | } |
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147 | return ' LIMIT '.$count; |
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148 | } |
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149 | |||
150 | /** |
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151 | * Read data from the specified SQL table |
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152 | * |
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153 | * @param string $tablename The name of the table to read from |
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154 | * @param string $where The where caluse of the SQL statement |
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155 | * @param string $select The colums to read |
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156 | * @param string $count The number of rows to read |
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157 | * @param string $skip The number of rows to skip over |
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158 | * @param array $sort The array to sort by or false to not sort |
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159 | * |
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160 | * @return array An array of all the returned records |
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161 | */ |
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162 | public function read($tablename, $where = false, $select = '*', $count = false, $skip = false, $sort = false) |
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163 | { |
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164 | if($select === false) |
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165 | { |
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166 | $select = '*'; |
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167 | } |
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168 | $sql = "SELECT $select FROM $tablename"; |
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169 | if($where !== false) |
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170 | { |
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171 | $sql .= ' WHERE '.$where; |
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172 | } |
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173 | $tmp = $this->getLimitClause($count, $skip) |
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174 | if($tmp !== false) |
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175 | { |
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176 | $sql .= $tmp; |
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177 | } |
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178 | $tmp = $this->getOrderByClause($sort); |
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179 | if($tmp !== false) |
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180 | { |
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181 | $sql .= $tmp; |
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182 | } |
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183 | $stmt = $this->pdo->query($sql, \PDO::FETCH_ASSOC); |
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184 | if($stmt === false) |
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185 | { |
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186 | return false; |
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187 | } |
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188 | $ret = $stmt->fetchAll(); |
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189 | if($ret === false || empty($ret)) |
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190 | { |
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191 | return false; |
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192 | } |
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193 | return $ret; |
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194 | } |
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195 | |||
196 | function update($tablename, $where, $data) |
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197 | { |
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198 | $set = array(); |
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199 | if(is_object($data)) |
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200 | { |
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201 | $data = (array)$data; |
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202 | } |
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203 | $cols = array_keys($data); |
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204 | $count = count($cols); |
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205 | for($i = 0; $i < $count; $i++) |
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206 | { |
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207 | array_push($set, $cols[$i].'='.$this->pdo->quote($data[$cols[$i]])); |
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208 | } |
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209 | $set = implode(',', $set); |
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210 | $sql = "UPDATE $tablename SET $set WHERE $where"; |
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211 | if($this->pdo->exec($sql) === false) |
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212 | { |
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213 | return false; |
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214 | } |
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215 | return true; |
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216 | } |
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217 | |||
218 | function create($tablename, $data) |
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219 | { |
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220 | $set = array(); |
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221 | if(is_object($data)) |
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222 | { |
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223 | $data = (array)$data; |
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224 | } |
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225 | $cols = array_keys($data); |
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226 | $count = count($cols); |
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227 | for($i = 0; $i < $count; $i++) |
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228 | { |
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229 | array_push($set, $this->pdo->quote($data[$cols[$i]])); |
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230 | } |
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231 | $cols = implode(',', $cols); |
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232 | $set = implode(',', $set); |
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233 | $sql = "INSERT INTO $tablename ($cols) VALUES ($set);"; |
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234 | if($this->pdo->exec($sql) === false) |
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235 | { |
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236 | return false; |
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237 | } |
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238 | return true; |
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239 | } |
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240 | |||
241 | function delete($tablename, $where) |
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263 |
Adding explicit visibility (
private
,protected
, orpublic
) is generally recommend to communicate to other developers how, and from where this method is intended to be used.