<?php
/**
* @file
* Database schema code for SQLite databases.
*/
/**
* @ingroup schemaapi
* @{
*/
class DatabaseSchema_sqlite extends DatabaseSchema {
/**
* Override DatabaseSchema::$defaultSchema
*/
protected $defaultSchema = 'main';
public function tableExists($table) {
$info = $this->getPrefixInfo($table);
// Don't use {} around sqlite_master table.
return (bool) $this->connection->query('SELECT 1 FROM ' . $info['schema'] . '.sqlite_master WHERE type = :type AND name = :name', array(':type' => 'table', ':name' => $info['table']))->fetchField();
}
public function fieldExists($table, $column) {
$schema = $this->introspectSchema($table);
return !empty($schema['fields'][$column]);
}
/**
* Generate SQL to create a new table from a Drupal schema definition.
*
* @param $name
* The name of the table to create.
* @param $table
* A Schema API table definition array.
* @return
* An array of SQL statements to create the table.
*/
public function createTableSql($name, $table) {
$sql = array();
$sql[] = "CREATE TABLE {" . $name . "} (\n" . $this->createColumsSql($name, $table) . "\n);\n";
return array_merge($sql, $this->createIndexSql($name, $table));
}
/**
* Build the SQL expression for indexes.
*/
protected function createIndexSql($tablename, $schema) {
$sql = array();
$info = $this->getPrefixInfo($tablename);
if (!empty($schema['unique keys'])) {
foreach ($schema['unique keys'] as $key => $fields) {
$sql[] = 'CREATE UNIQUE INDEX ' . $info['schema'] . '.' . $info['table'] . '_' . $key . ' ON ' . $info['table'] . ' (' . $this->createKeySql($fields) . "); \n";
}
}
if (!empty($schema['indexes'])) {
foreach ($schema['indexes'] as $key => $fields) {
$sql[] = 'CREATE INDEX ' . $info['schema'] . '.' . $info['table'] . '_' . $key . ' ON ' . $info['table'] . ' (' . $this->createKeySql($fields) . "); \n";
}
}
return $sql;
}
/**
* Build the SQL expression for creating columns.
*/
protected function createColumsSql($tablename, $schema) {
$sql_array = array();
// Add the SQL statement for each field.
foreach ($schema['fields'] as $name => $field) {
if (isset($field['type']) && $field['type'] == 'serial') {
if (isset($schema['primary key']) && ($key = array_search($name, $schema['primary key'])) !== FALSE) {
unset($schema['primary key'][$key]);
}
}
$sql_array[] = $this->createFieldSql($name, $this->processField($field));
}
// Process keys.
if (!empty($schema['primary key'])) {
$sql_array[] = " PRIMARY KEY (" . $this->createKeySql($schema['primary key']) . ")";
}
return implode(", \n", $sql_array);
}
/**
* Build the SQL expression for keys.
*/
protected function createKeySql($fields) {
$return = array();
foreach ($fields as $field) {
if (is_array($field)) {
$return[] = $field[0];
}
else {
$return[] = $field;
}
}
return implode(', ', $return);
}
/**
* Set database-engine specific properties for a field.
*
* @param $field
* A field description array, as specified in the schema documentation.
*/
protected function processField($field) {
if (!isset($field['size'])) {
$field['size'] = 'normal';
}
// Set the correct database-engine specific datatype.
// In case one is already provided, force it to uppercase.
if (isset($field['sqlite_type'])) {
$field['sqlite_type'] = drupal_strtoupper($field['sqlite_type']);
}
else {
$map = $this->getFieldTypeMap();
$field['sqlite_type'] = $map[$field['type'] . ':' . $field['size']];
}
if (isset($field['type']) && $field['type'] == 'serial') {
$field['auto_increment'] = TRUE;
}
return $field;
}
/**
* Create an SQL string for a field to be used in table creation or alteration.
*
* Before passing a field out of a schema definition into this function it has
* to be processed by db_processField().
*
* @param $name
* Name of the field.
* @param $spec
* The field specification, as per the schema data structure format.
*/
protected function createFieldSql($name, $spec) {
if (!empty($spec['auto_increment'])) {
$sql = $name . " INTEGER PRIMARY KEY AUTOINCREMENT";
if (!empty($spec['unsigned'])) {
$sql .= ' CHECK (' . $name . '>= 0)';
}
}
else {
$sql = $name . ' ' . $spec['sqlite_type'];
if (in_array($spec['sqlite_type'], array('VARCHAR', 'TEXT')) && isset($spec['length'])) {
$sql .= '(' . $spec['length'] . ')';
}
if (isset($spec['not null'])) {
if ($spec['not null']) {
$sql .= ' NOT NULL';
}
else {
$sql .= ' NULL';
}
}
if (!empty($spec['unsigned'])) {
$sql .= ' CHECK (' . $name . '>= 0)';
}
if (isset($spec['default'])) {
if (is_string($spec['default'])) {
$spec['default'] = "'" . $spec['default'] . "'";
}
$sql .= ' DEFAULT ' . $spec['default'];
}
if (empty($spec['not null']) && !isset($spec['default'])) {
$sql .= ' DEFAULT NULL';
}
}
return $sql;
}
/**
* This maps a generic data type in combination with its data size
* to the engine-specific data type.
*/
public function getFieldTypeMap() {
// Put :normal last so it gets preserved by array_flip. This makes
// it much easier for modules (such as schema.module) to map
// database types back into schema types.
// $map does not use drupal_static as its value never changes.
static $map = array(
'varchar:normal' => 'VARCHAR',
'char:normal' => 'CHAR',
'text:tiny' => 'TEXT',
'text:small' => 'TEXT',
'text:medium' => 'TEXT',
'text:big' => 'TEXT',
'text:normal' => 'TEXT',
'serial:tiny' => 'INTEGER',
'serial:small' => 'INTEGER',
'serial:medium' => 'INTEGER',
'serial:big' => 'INTEGER',
'serial:normal' => 'INTEGER',
'int:tiny' => 'INTEGER',
'int:small' => 'INTEGER',
'int:medium' => 'INTEGER',
'int:big' => 'INTEGER',
'int:normal' => 'INTEGER',
'float:tiny' => 'FLOAT',
'float:small' => 'FLOAT',
'float:medium' => 'FLOAT',
'float:big' => 'FLOAT',
'float:normal' => 'FLOAT',
'numeric:normal' => 'NUMERIC',
'blob:big' => 'BLOB',
'blob:normal' => 'BLOB',
);
return $map;
}
public function renameTable($table, $new_name) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename @table to @table_new: table @table doesn't exist.", array('@table' => $table, '@table_new' => $new_name)));
}
if ($this->tableExists($new_name)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot rename @table to @table_new: table @table_new already exists.", array('@table' => $table, '@table_new' => $new_name)));
}
$schema = $this->introspectSchema($table);
// SQLite doesn't allow you to rename tables outside of the current
// database. So the syntax '...RENAME TO database.table' would fail.
// So we must determine the full table name here rather than surrounding
// the table with curly braces incase the db_prefix contains a reference
// to a database outside of our existing database.
$info = $this->getPrefixInfo($new_name);
$this->connection->query('ALTER TABLE {' . $table . '} RENAME TO ' . $info['table']);
// Drop the indexes, there is no RENAME INDEX command in SQLite.
if (!empty($schema['unique keys'])) {
foreach ($schema['unique keys'] as $key => $fields) {
$this->dropIndex($table, $key);
}
}
if (!empty($schema['indexes'])) {
foreach ($schema['indexes'] as $index => $fields) {
$this->dropIndex($table, $index);
}
}
// Recreate the indexes.
$statements = $this->createIndexSql($new_name, $schema);
foreach ($statements as $statement) {
$this->connection->query($statement);
}
}
public function dropTable($table) {
if (!$this->tableExists($table)) {
return FALSE;
}
$this->connection->tableDropped = TRUE;
$this->connection->query('DROP TABLE {' . $table . '}');
return TRUE;
}
public function addField($table, $field, $specification, $keys_new = array()) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field @table.@field: table doesn't exist.", array('@field' => $field, '@table' => $table)));
}
if ($this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", array('@field' => $field, '@table' => $table)));
}
// SQLite doesn't have a full-featured ALTER TABLE statement. It only
// supports adding new fields to a table, in some simple cases. In most
// cases, we have to create a new table and copy the data over.
if (empty($keys_new) && (empty($specification['not null']) || isset($specification['default']))) {
// When we don't have to create new keys and we are not creating a
// NOT NULL column without a default value, we can use the quicker version.
$query = 'ALTER TABLE {' . $table . '} ADD ' . $this->createFieldSql($field, $this->processField($specification));
$this->connection->query($query);
// Apply the initial value if set.
if (isset($specification['initial'])) {
$this->connection->update($table)
->fields(array($field => $specification['initial']))
->execute();
}
}
else {
// We cannot add the field directly. Use the slower table alteration
// method, starting from the old schema.
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
// Add the new field.
$new_schema['fields'][$field] = $specification;
// Build the mapping between the old fields and the new fields.
$mapping = array();
if (isset($specification['initial'])) {
// If we have a initial value, copy it over.
$mapping[$field] = array(
'expression' => ':newfieldinitial',
'arguments' => array(':newfieldinitial' => $specification['initial']),
);
}
else {
// Else use the default of the field.
$mapping[$field] = NULL;
}
// Add the new indexes.
$new_schema += $keys_new;
$this->alterTable($table, $old_schema, $new_schema, $mapping);
}
}
/**
* Create a table with a new schema containing the old content.
*
* As SQLite does not support ALTER TABLE (with a few exceptions) it is
* necessary to create a new table and copy over the old content.
*
* @param $table
* Name of the table to be altered.
* @param $old_schema
* The old schema array for the table.
* @param $new_schema
* The new schema array for the table.
* @param $mapping
* An optional mapping between the fields of the old specification and the
* fields of the new specification. An associative array, whose keys are
* the fields of the new table, and values can take two possible forms:
* - a simple string, which is interpreted as the name of a field of the
* old table,
* - an associative array with two keys 'expression' and 'arguments',
* that will be used as an expression field.
*/
protected function alterTable($table, $old_schema, $new_schema, array $mapping = array()) {
$i = 0;
do {
$new_table = $table . '_' . $i++;
} while ($this->tableExists($new_table));
$this->createTable($new_table, $new_schema);
// Build a SQL query to migrate the data from the old table to the new.
$select = $this->connection->select($table);
// Complete the mapping.
$possible_keys = array_keys($new_schema['fields']);
$mapping += array_combine($possible_keys, $possible_keys);
// Now add the fields.
foreach ($mapping as $field_alias => $field_source) {
// Just ignore this field (ie. use it's default value).
if (!isset($field_source)) {
continue;
}
if (is_array($field_source)) {
$select->addExpression($field_source['expression'], $field_alias, $field_source['arguments']);
}
else {
$select->addField($table, $field_source, $field_alias);
}
}
// Execute the data migration query.
$this->connection->insert($new_table)
->from($select)
->execute();
$old_count = $this->connection->query('SELECT COUNT(*) FROM {' . $table . '}')->fetchField();
$new_count = $this->connection->query('SELECT COUNT(*) FROM {' . $new_table . '}')->fetchField();
if ($old_count == $new_count) {
$this->dropTable($table);
$this->renameTable($new_table, $table);
}
}
/**
* Find out the schema of a table.
*
* This function uses introspection methods provided by the database to
* create a schema array. This is useful, for example, during update when
* the old schema is not available.
*
* @param $table
* Name of the table.
* @return
* An array representing the schema, from drupal_get_schema().
* @see drupal_get_schema()
*/
protected function introspectSchema($table) {
$mapped_fields = array_flip($this->getFieldTypeMap());
$schema = array(
'fields' => array(),
'primary key' => array(),
'unique keys' => array(),
'indexes' => array(),
);
$info = $this->getPrefixInfo($table);
$result = $this->connection->query('PRAGMA ' . $info['schema'] . '.table_info(' . $info['table'] . ')');
foreach ($result as $row) {
if (preg_match('/^([^(]+)\((.*)\)$/', $row->type, $matches)) {
$type = $matches[1];
$length = $matches[2];
}
else {
$type = $row->type;
$length = NULL;
}
if (isset($mapped_fields[$type])) {
list($type, $size) = explode(':', $mapped_fields[$type]);
$schema['fields'][$row->name] = array(
'type' => $type,
'size' => $size,
'not null' => !empty($row->notnull),
'default' => trim((string) $row->dflt_value, "'"),
);
if ($length) {
$schema['fields'][$row->name]['length'] = $length;
}
if ($row->pk) {
$schema['primary key'][] = $row->name;
}
}
else {
new Exception("Unable to parse the column type " . $row->type);
}
}
$indexes = array();
$result = $this->connection->query('PRAGMA ' . $info['schema'] . '.index_list(' . $info['table'] . ')');
foreach ($result as $row) {
if (strpos($row->name, 'sqlite_autoindex_') !== 0) {
$indexes[] = array(
'schema_key' => $row->unique ? 'unique keys' : 'indexes',
'name' => $row->name,
);
}
}
foreach ($indexes as $index) {
$name = $index['name'];
// Get index name without prefix.
$index_name = substr($name, strlen($info['table']) + 1);
$result = $this->connection->query('PRAGMA ' . $info['schema'] . '.index_info(' . $name . ')');
foreach ($result as $row) {
$schema[$index['schema_key']][$index_name][] = $row->name;
}
}
return $schema;
}
public function dropField($table, $field) {
if (!$this->fieldExists($table, $field)) {
return FALSE;
}
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
unset($new_schema['fields'][$field]);
foreach ($new_schema['indexes'] as $index => $fields) {
foreach ($fields as $key => $field_name) {
if ($field_name == $field) {
unset($new_schema['indexes'][$index][$key]);
}
}
// If this index has no more fields then remove it.
if (empty($new_schema['indexes'][$index])) {
unset($new_schema['indexes'][$index]);
}
}
$this->alterTable($table, $old_schema, $new_schema);
return TRUE;
}
public function changeField($table, $field, $field_new, $spec, $keys_new = array()) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array('@table' => $table, '@name' => $field)));
}
if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array('@table' => $table, '@name' => $field, '@name_new' => $field_new)));
}
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
// Map the old field to the new field.
if ($field != $field_new) {
$mapping[$field_new] = $field;
}
else {
$mapping = array();
}
// Remove the previous definition and swap in the new one.
unset($new_schema['fields'][$field]);
$new_schema['fields'][$field_new] = $spec;
// Map the former indexes to the new column name.
$new_schema['primary key'] = $this->mapKeyDefinition($new_schema['primary key'], $mapping);
foreach (array('unique keys', 'indexes') as $k) {
foreach ($new_schema[$k] as &$key_definition) {
$key_definition = $this->mapKeyDefinition($key_definition, $mapping);
}
}
// Add in the keys from $keys_new.
if (isset($keys_new['primary key'])) {
$new_schema['primary key'] = $keys_new['primary key'];
}
foreach (array('unique keys', 'indexes') as $k) {
if (!empty($keys_new[$k])) {
$new_schema[$k] = $keys_new[$k] + $new_schema[$k];
}
}
$this->alterTable($table, $old_schema, $new_schema, $mapping);
}
/**
* Utility method: rename columns in an index definition according to a new mapping.
*
* @param $key_definition
* The key definition.
* @param $mapping
* The new mapping.
*/
protected function mapKeyDefinition(array $key_definition, array $mapping) {
foreach ($key_definition as &$field) {
// The key definition can be an array($field, $length).
if (is_array($field)) {
$field = &$field[0];
}
if (isset($mapping[$field])) {
$field = $mapping[$field];
}
}
return $key_definition;
}
public function addIndex($table, $name, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
}
if ($this->indexExists($table, $name)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add index @name to table @table: index already exists.", array('@table' => $table, '@name' => $name)));
}
$schema['indexes'][$name] = $fields;
$statements = $this->createIndexSql($table, $schema);
foreach ($statements as $statement) {
$this->connection->query($statement);
}
}
public function indexExists($table, $name) {
$info = $this->getPrefixInfo($table);
return $this->connection->query('PRAGMA ' . $info['schema'] . '.index_info(' . $info['table'] . '_' . $name . ')')->fetchField() != '';
}
public function dropIndex($table, $name) {
if (!$this->indexExists($table, $name)) {
return FALSE;
}
$info = $this->getPrefixInfo($table);
$this->connection->query('DROP INDEX ' . $info['schema'] . '.' . $info['table'] . '_' . $name);
return TRUE;
}
public function addUniqueKey($table, $name, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
}
if ($this->indexExists($table, $name)) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table @table: unique key already exists.", array('@table' => $table, '@name' => $name)));
}
$schema['unique keys'][$name] = $fields;
$statements = $this->createIndexSql($table, $schema);
foreach ($statements as $statement) {
$this->connection->query($statement);
}
}
public function dropUniqueKey($table, $name) {
if (!$this->indexExists($table, $name)) {
return FALSE;
}
$info = $this->getPrefixInfo($table);
$this->connection->query('DROP INDEX ' . $info['schema'] . '.' . $info['table'] . '_' . $name);
return TRUE;
}
public function addPrimaryKey($table, $fields) {
if (!$this->tableExists($table)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table @table: table doesn't exist.", array('@table' => $table)));
}
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
if (!empty($new_schema['primary key'])) {
throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table @table: primary key already exists.", array('@table' => $table)));
}
$new_schema['primary key'] = $fields;
$this->alterTable($table, $old_schema, $new_schema);
}
public function dropPrimaryKey($table) {
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
if (empty($new_schema['primary key'])) {
return FALSE;
}
unset($new_schema['primary key']);
$this->alterTable($table, $old_schema, $new_schema);
return TRUE;
}
public function fieldSetDefault($table, $field, $default) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot set default value of field @table.@field: field doesn't exist.", array('@table' => $table, '@field' => $field)));
}
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
$new_schema['fields'][$field]['default'] = $default;
$this->alterTable($table, $old_schema, $new_schema);
}
public function fieldSetNoDefault($table, $field) {
if (!$this->fieldExists($table, $field)) {
throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot remove default value of field @table.@field: field doesn't exist.", array('@table' => $table, '@field' => $field)));
}
$old_schema = $this->introspectSchema($table);
$new_schema = $old_schema;
unset($new_schema['fields'][$field]['default']);
$this->alterTable($table, $old_schema, $new_schema);
}
/**
* {@inheritdoc}
*/
public function findTables($table_expression) {
// Don't add the prefix, $table_expression already includes the prefix.
$info = $this->getPrefixInfo($table_expression, FALSE);
// Can't use query placeholders for the schema because the query would have
// to be :prefixsqlite_master, which does not work.
$result = db_query("SELECT name FROM " . $info['schema'] . ".sqlite_master WHERE type = :type AND name LIKE :table_name", array(
':type' => 'table',
':table_name' => $info['table'],
));
return $result->fetchAllKeyed(0, 0);
}
/**
* {@inheritdoc}
*/
public function findTablesD8($table_expression) {
$tables = array();
// The SQLite implementation doesn't need to use the same filtering strategy
// as the parent one because individually prefixed tables live in their own
// schema (database), which means that neither the main database nor any
// attached one will contain a prefixed table name, so we just need to loop
// over all known schemas and filter by the user-supplied table expression.
$attached_dbs = $this->connection->getAttachedDatabases();
foreach ($attached_dbs as $schema) {
// Can't use query placeholders for the schema because the query would
// have to be :prefixsqlite_master, which does not work. We also need to
// ignore the internal SQLite tables.
$result = db_query("SELECT name FROM " . $schema . ".sqlite_master WHERE type = :type AND name LIKE :table_name AND name NOT LIKE :pattern", array(
':type' => 'table',
':table_name' => $table_expression,
':pattern' => 'sqlite_%',
));
$tables += $result->fetchAllKeyed(0, 0);
}
return $tables;
}
}