1 <?php

     2 

     3 /**

     4  * @file

     5  * Query code for SQLite embedded database engine.

     6  */

     7 

     8 /**

     9  * @addtogroup database

    10  * @{

    11  */

    12 

    13 /**

    14  * SQLite specific implementation of InsertQuery.

    15  *

    16  * We ignore all the default fields and use the clever SQLite syntax:

    17  *   INSERT INTO table DEFAULT VALUES

    18  * for degenerated "default only" queries.

    19  */

    20 class InsertQuery_sqlite extends InsertQuery {

    21 

    22   public function execute() {

    23     if (!$this->preExecute()) {

    24       return NULL;

    25     }

    26     if (count($this->insertFields)) {

    27       return parent::execute();

    28     }

    29     else {

    30       return $this->connection->query('INSERT INTO {' . $this->table . '} DEFAULT VALUES', array(), $this->queryOptions);

    31     }

    32   }

    33 

    34   public function __toString() {

    35     // Create a sanitized comment string to prepend to the query.

    36     $comments = $this->connection->makeComment($this->comments);

    37 

    38     // Produce as many generic placeholders as necessary.

    39     $placeholders = array_fill(0, count($this->insertFields), '?');

    40 

    41     // If we're selecting from a SelectQuery, finish building the query and

    42     // pass it back, as any remaining options are irrelevant.

    43     if (!empty($this->fromQuery)) {

    44       $insert_fields_string = $this->insertFields ? ' (' . implode(', ', $this->insertFields) . ') ' : ' ';

    45       return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;

    46     }

    47 

    48     return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $this->insertFields) . ') VALUES (' . implode(', ', $placeholders) . ')';

    49   }

    50 

    51 }

    52 

    53 /**

    54  * SQLite specific implementation of UpdateQuery.

    55  *

    56  * SQLite counts all the rows that match the conditions as modified, even if they

    57  * will not be affected by the query. We workaround this by ensuring that

    58  * we don't select those rows.

    59  *

    60  * A query like this one:

    61  *   UPDATE test SET col1 = 'newcol1', col2 = 'newcol2' WHERE tid = 1

    62  * will become:

    63  *   UPDATE test SET col1 = 'newcol1', col2 = 'newcol2' WHERE tid = 1 AND (col1 <> 'newcol1' OR col2 <> 'newcol2')

    64  */

    65 class UpdateQuery_sqlite extends UpdateQuery {

    66   public function execute() {

    67     if (!empty($this->queryOptions['sqlite_return_matched_rows'])) {

    68       return parent::execute();

    69     }

    70 

    71     // Get the fields used in the update query.

    72     $fields = $this->expressionFields + $this->fields;

    73 

    74     // Add the inverse of the fields to the condition.

    75     $condition = new DatabaseCondition('OR');

    76     foreach ($fields as $field => $data) {

    77       if (is_array($data)) {

    78         // The field is an expression.

    79         $condition->where($field . ' <> ' . $data['expression']);

    80         $condition->isNull($field);

    81       }

    82       elseif (!isset($data)) {

    83         // The field will be set to NULL.

    84         $condition->isNotNull($field);

    85       }

    86       else {

    87         $condition->condition($field, $data, '<>');

    88         $condition->isNull($field);

    89       }

    90     }

    91     if (count($condition)) {

    92       $condition->compile($this->connection, $this);

    93       $this->condition->where((string) $condition, $condition->arguments());

    94     }

    95     return parent::execute();

    96   }

    97 

    98 }

    99 

   100 /**

   101  * SQLite specific implementation of DeleteQuery.

   102  */

   103 class DeleteQuery_sqlite extends DeleteQuery {

   104   public function execute() {

   105     // When the WHERE is omitted from a DELETE statement and the table being

   106     // deleted has no triggers, SQLite uses an optimization to erase the entire

   107     // table content without having to visit each row of the table individually.

   108     // Prior to SQLite 3.6.5, SQLite does not return the actual number of rows

   109     // deleted by that optimized "truncate" optimization. But we want to return

   110     // the number of rows affected, so we calculate it directly.

   111     if (!count($this->condition)) {

   112       $total_rows = $this->connection->query('SELECT COUNT(*) FROM {' . $this->connection->escapeTable($this->table) . '}')->fetchField();

   113       parent::execute();

   114       return $total_rows;

   115     }

   116     else {

   117       return parent::execute();

   118     }

   119   }

   120 }

   121 

   122 /**

   123  * SQLite specific implementation of TruncateQuery.

   124  *

   125  * SQLite doesn't support TRUNCATE, but a DELETE query with no condition has

   126  * exactly the effect (it is implemented by DROPing the table).

   127  */

   128 class TruncateQuery_sqlite extends TruncateQuery {

   129   public function __toString() {

   130     // Create a sanitized comment string to prepend to the query.

   131     $comments = $this->connection->makeComment($this->comments);

   132 

   133     return $comments . 'DELETE FROM {' . $this->connection->escapeTable($this->table) . '} ';

   134   }

   135 }

   136 

   137 /**

   138  * @} End of "addtogroup database".

   139  */