Total Complexity | 48 |
Total Lines | 203 |
Duplicated Lines | 0 % |
Changes | 2 | ||
Bugs | 0 | Features | 0 |
Complex classes like DbConn 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.
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 DbConn, and based on these observations, apply Extract Interface, too.
1 | <?php |
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24 | class DbConn { |
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25 | var $db_conn; // a mysqli object |
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26 | var $db_name; // the DB name |
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27 | |||
28 | function init_conn($user, $passwd, $host, $name) { |
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55 | } |
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56 | |||
57 | function close() { |
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58 | if ($this->db_conn) { |
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59 | $this->db_conn->close(); |
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60 | } |
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61 | } |
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62 | |||
63 | // in keeping with PHP/MySQL convention, return true (nonzero) on success. |
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64 | // (This is the opposite of the BOINC convention) |
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65 | // |
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66 | function do_query($q) { |
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67 | global $generating_xml; |
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68 | $q = str_replace('DBNAME', $this->db_name, $q); |
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69 | //echo "query: $q<br>\n"; |
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70 | $ret = $this->db_conn->query($q); |
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71 | if (!$ret) { |
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72 | if (!$generating_xml) { |
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73 | echo "Database Error<br>\n"; |
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74 | } |
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75 | //echo ": ", $this->base_error(), "\n<pre>"; |
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76 | //var_dump(debug_backtrace()); |
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77 | //echo "</pre>query: $q\n"; |
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78 | return null; |
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79 | } |
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80 | return $ret; |
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81 | } |
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82 | |||
83 | // # rows affected by last query |
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84 | // |
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85 | function affected_rows() { |
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86 | return $this->db_conn->affected_rows; |
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87 | } |
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88 | |||
89 | function get_list($table1, $table2, $joinfield1, $joinfield2, $classname, $fields, $where_clause, $order_clause, $limit) { |
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99 | } |
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100 | |||
101 | function lookup_fields($table, $classname, $fields, $clause) { |
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102 | $query = "select $fields from DBNAME.$table where $clause"; |
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103 | $result = $this->do_query($query); |
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104 | if (!$result) { |
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105 | return null; |
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106 | } |
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107 | $obj = $result->fetch_object($classname); |
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108 | $result->free(); |
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109 | return $obj; |
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110 | } |
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111 | |||
112 | function lookup($table, $classname, $clause) { |
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113 | return $this->lookup_fields($table, $classname, "*", $clause); |
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114 | } |
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115 | |||
116 | function lookup_id($id, $table, $classname) { |
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117 | $id = (int)$id; |
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118 | return $this->lookup($table, $classname, "id=$id"); |
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119 | } |
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120 | |||
121 | function enum_general($classname, $query) { |
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122 | $result = $this->do_query($query); |
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123 | if (!$result) return null; |
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124 | $x = array(); |
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125 | while ($obj = $result->fetch_object($classname)) { |
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126 | $x[] = $obj; |
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127 | } |
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128 | $result->free(); |
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129 | return $x; |
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130 | } |
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131 | |||
132 | function enum_fields( |
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141 | } |
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142 | |||
143 | function enum($table, $classname, $where_clause=null, $order_clause=null) { |
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144 | return self::enum_fields( |
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145 | $table, $classname, '*', $where_clause, $order_clause |
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146 | ); |
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147 | } |
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148 | |||
149 | function update($obj, $table, $clause) { |
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150 | $query = "update DBNAME.$table set $clause where id=$obj->id"; |
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151 | return $this->do_query($query); |
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152 | } |
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153 | function update_aux($table, $clause) { |
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154 | $query = "update DBNAME.$table set $clause"; |
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155 | return $this->do_query($query); |
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156 | } |
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157 | function insert($table, $clause) { |
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158 | $query = "insert into DBNAME.$table $clause"; |
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159 | return $this->do_query($query); |
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160 | } |
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161 | function delete($obj, $table) { |
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162 | $query = "delete from DBNAME.$table where id=$obj->id"; |
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163 | return $this->do_query($query); |
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164 | } |
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165 | function delete_aux($table, $clause) { |
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166 | $query = "delete from DBNAME.$table where $clause"; |
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167 | return $this->do_query($query); |
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168 | } |
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169 | function insert_id() { |
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170 | return $this->db_conn->insert_id; |
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171 | } |
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172 | function get_int($query, $field) { |
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173 | $result = $this->do_query($query); |
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174 | if (!$result) error_page("database error on query $query"); |
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175 | $x = $result->fetch_object("StdClass"); |
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176 | $result->free(); |
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177 | if ($x) return $x->$field; |
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178 | return false; |
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179 | } |
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180 | function get_double($query, $field) { |
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181 | $result = $this->do_query($query); |
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182 | if (!$result) error_page("database error on query $query"); |
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183 | $x = $result->fetch_object("StdClass"); |
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184 | $result->free(); |
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185 | if ($x) return (double)$x->$field; |
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186 | return false; |
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187 | } |
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188 | function count($table, $clause="TRUE") { |
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189 | $query = "select count(*) as total from DBNAME.$table where $clause"; |
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190 | return $this->get_int($query, 'total'); |
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191 | } |
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192 | function sum($table, $field, $clause="") { |
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193 | $query = "select sum($field) as total from DBNAME.$table $clause"; |
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194 | return $this->get_double($query, 'total'); |
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195 | } |
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196 | function max($table, $field, $clause="") { |
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197 | $query = "select max($field) as total from DBNAME.$table $clause"; |
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198 | return $this->get_double($query, 'total'); |
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199 | } |
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200 | function percentile($table, $field, $clause, $pct) { |
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201 | $n = $this->count($table, $clause); |
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202 | if (!$n) return false; |
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203 | $m = (int)($n*$pct/100); |
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204 | $query = "select $field from DBNAME.$table where $clause order by $field limit $m,1"; |
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205 | return $this->get_double($query, $field); |
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206 | } |
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207 | function replace($table, $clause) { |
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208 | $query = "replace into DBNAME.$table set $clause"; |
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209 | return $this->do_query($query); |
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210 | } |
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211 | function base_escape_string($string) { |
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212 | return $this->db_conn->escape_string($string); |
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213 | } |
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214 | function base_error() { |
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215 | return $this->db_conn->error; |
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216 | } |
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217 | function base_errno() { |
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218 | return $this->db_conn->errno; |
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219 | } |
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220 | function table_exists($table_name) { |
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227 | } |
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228 | } |
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229 | |||
230 | ?> |
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231 |