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<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
namespace Wikimedia\Rdbms\Platform;
use Wikimedia\Rdbms\DBError;
use Wikimedia\Rdbms\LikeMatch;
use Wikimedia\Rdbms\Subquery;
/**
* Interface for query language.
* Note: This is for simple SQL operations, use query builder classes for building full queries.
*
* Methods of this interface should be only used by rdbms library.
* @since 1.39
*/
interface ISQLPlatform {
/** @var int Combine list with comma delimiters */
public const LIST_COMMA = 0;
/** @var int Combine list with AND clauses */
public const LIST_AND = 1;
/** @var int Convert map into a SET clause */
public const LIST_SET = 2;
/** @var int Treat as field name and do not apply value escaping */
public const LIST_NAMES = 3;
/** @var int Combine list with OR clauses */
public const LIST_OR = 4;
/** @var string Unconditional update/delete of whole table */
public const ALL_ROWS = '*';
/** @var int Idiom for "no special flags" */
public const QUERY_NORMAL = 0;
/** @var int Ignore query errors and return false when they happen */
public const QUERY_SILENCE_ERRORS = 1; // b/c for 1.32 query() argument; (int)true = 1
/** Track a TEMPORARY table CREATE as if it was for a permanent table (for testing) */
public const QUERY_PSEUDO_PERMANENT = 2;
/** @var int Enforce that a query does not make effective writes */
public const QUERY_REPLICA_ROLE = 4;
/** @var int Ignore the current presence of any DBO_TRX flag */
public const QUERY_IGNORE_DBO_TRX = 8;
/** @var int Do not try to retry the query if the connection was lost */
public const QUERY_NO_RETRY = 16;
/** @var int Query is a read-only Data Query Language query */
public const QUERY_CHANGE_NONE = 32;
/** @var int Query is a Transaction Control Language command (BEGIN, USE, SET, ...) */
public const QUERY_CHANGE_TRX = 64 | self::QUERY_IGNORE_DBO_TRX;
/** @var int Query is a Data Manipulation Language command (INSERT, DELETE, LOCK, ...) */
public const QUERY_CHANGE_ROWS = 128;
/** @var int Query is a Data Definition Language command */
public const QUERY_CHANGE_SCHEMA = 256 | self::QUERY_IGNORE_DBO_TRX;
/** @var int Query is a command for advisory locks */
public const QUERY_CHANGE_LOCKS = 512 | self::QUERY_IGNORE_DBO_TRX;
/**
* @param string|int $field
* @return string
*/
public function bitNot( $field );
/**
* @param string|int $fieldLeft
* @param string|int $fieldRight
* @return string
*/
public function bitAnd( $fieldLeft, $fieldRight );
/**
* @param string|int $fieldLeft
* @param string|int $fieldRight
* @return string
*/
public function bitOr( $fieldLeft, $fieldRight );
/**
* Escape a SQL identifier (e.g. table, column, database) for use in a SQL query
*
* Depending on the database this will either be `backticks` or "double quotes"
*
* @param string $s
* @param-taint $s escapes_sql NOTE: this is subpar, as addIdentifierQuotes isn't always the right type of escaping.
* @return string
* @return-taint none
* @since 1.33
*/
public function addIdentifierQuotes( $s );
/**
* Build a GREATEST function statement comparing columns/values
*
* Integer and float values in $values will not be quoted
*
* If $fields is an array, then each value with a string key is treated as an expression
* (which must be manually quoted); such string keys do not appear in the SQL and are only
* descriptive aliases.
*
* @param string|string[] $fields Name(s) of column(s) with values to compare
* @param string|int|float|string[]|int[]|float[] $values Values to compare
* @return mixed
* @since 1.35 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function buildGreatest( $fields, $values );
/**
* Build a LEAST function statement comparing columns/values
*
* Integer and float values in $values will not be quoted
*
* If $fields is an array, then each value with a string key is treated as an expression
* (which must be manually quoted); such string keys do not appear in the SQL and are only
* descriptive aliases.
*
* @param string|string[] $fields Name(s) of column(s) with values to compare
* @param string|int|float|string[]|int[]|float[] $values Values to compare
* @return mixed
* @since 1.35 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function buildLeast( $fields, $values );
/**
* Build a condition comparing multiple values, for use with indexes that cover
* multiple fields, common when e.g. paging through results or doing batch operations.
*
* For example, you might be displaying a list of people ordered alphabetically by their last
* and first name, split across multiple pages. The first page of the results ended at Jane Doe.
* When building the query for the next page, you would use:
*
* $queryBuilder->where( $db->buildComparison( '>', [ 'last' => 'Doe', 'first' => 'Jane' ] ) );
*
* This will return people whose last name follows Doe, or whose last name is Doe and first name
* follows Jane.
*
* Note that the order of keys in the associative array $conds is significant,
* and must match the order of fields used by the index.
*
* You might also use it to generate a simple comparison without writing raw SQL:
*
* $db->buildComparison( '<=', [ 'key' => $val ] )
* // equivalent to:
* 'key <= ' . $db->addQuotes( $val )
*
* @param string $op Comparison operator, one of '>', '>=', '<', '<='
* @param array $conds Map of field names to their values to use in the comparison
* @return string SQL code
*/
public function buildComparison( string $op, array $conds ): string;
/**
* Makes an encoded list of strings from an array
*
* These can be used to make conjunctions or disjunctions on SQL condition strings
* derived from an array ({@see IDatabase::select} $conds documentation).
*
* Example usage:
* @code
* $sql = $db->makeList( [
* 'rev_page' => $id,
* $db->makeList( [ 'rev_minor' => 1, 'rev_len < 500' ], $db::LIST_OR )
* ], $db::LIST_AND );
* @endcode
* This would set $sql to "rev_page = '$id' AND (rev_minor = 1 OR rev_len < 500)"
*
* @param array $a Containing the data
* @param-taint $a escapes_sql - Note, this is also special-cased in MediaWikiSecurityCheckPlugin
* @param int $mode IDatabase class constant:
* - IDatabase::LIST_COMMA: Comma separated, no field names
* - IDatabase::LIST_AND: ANDed WHERE clause (without the WHERE).
* - IDatabase::LIST_OR: ORed WHERE clause (without the WHERE)
* - IDatabase::LIST_SET: Comma separated with field names, like a SET clause
* - IDatabase::LIST_NAMES: Comma separated field names
* @param-taint $mode none
* @throws DBError If an error occurs, {@see IDatabase::query}
* @return string
* @return-taint none
*/
public function makeList( array $a, $mode = self::LIST_COMMA );
/**
* Build a "OR" condition with pairs from a two-dimensional array.
*
* The associative array should have integer keys relating to the $baseKey field.
* The nested array should have string keys for the $subKey field. The inner
* values are ignored, and are typically boolean true.
*
* Example usage:
* ```
* $data = [
* 2 => [
* 'Foo' => true,
* 'Bar' => true,
* ],
* 3 => [
* 'Quux' => true,
* ],
* ];
* // (page_namespace = 2 AND page_title IN ('Foo','Bar'))
* // OR (page_namespace = 3 AND page_title = 'Quux')
* ```
* @todo This is effectively specific to MediaWiki's LinkBatch.
* Consider deprecating or generalising slightly.
*
* @param array $data Nested array, must be non-empty
* @phan-param non-empty-array $data
* @param string $baseKey Field name to match the base-level keys to (eg 'pl_namespace')
* @param string $subKey Field name to match the sub-level keys to (eg 'pl_title')
* @return string SQL fragment
*/
public function makeWhereFrom2d( $data, $baseKey, $subKey );
/**
* Given an array of condition arrays representing an OR list of AND lists,
* for example:
*
* (A=1 AND B=2) OR (A=1 AND B=3)
*
* produce an SQL expression in which the conditions are factored:
*
* (A=1 AND (B=2 OR B=3))
*
* We also use IN() to simplify further:
*
* (A=1 AND (B IN (2,3))
*
* More compactly, in boolean algebra notation, a sum of products, e.g.
* AB + AC is factored to produce A(B+C). Factoring proceeds recursively
* to reduce expressions with any number of variables, for example
* AEP + AEQ + AFP + AFQ = A(E(P+Q) + F(P+Q))
*
* The algorithm is simple and will not necessarily find the shortest
* possible expression. For the best results, fields should be given in a
* consistent order, and the fields with values likely to be shared should
* be leftmost in the associative arrays.
*
* @param array $condsArray An array of associative arrays. The associative
* array keys represent field names, and the values represent the field
* values to compare against.
* @return string SQL expression fragment
*/
public function factorConds( $condsArray );
/**
* Build a concatenation list to feed into a SQL query
* @param string[] $stringList Raw SQL expression list; caller is responsible for escaping
* @return string
*/
public function buildConcat( $stringList );
/**
* Construct a LIMIT query with optional offset
*
* The SQL should be adjusted so that only the first $limit rows
* are returned. If $offset is provided as well, then the first $offset
* rows should be discarded, and the next $limit rows should be returned.
* If the result of the query is not ordered, then the rows to be returned
* are theoretically arbitrary.
*
* $sql is expected to be a SELECT, if that makes a difference.
*
* @param string $sql SQL query we will append the limit too
* @param int $limit The SQL limit
* @param int|false $offset The SQL offset (default false)
* @return string
* @since 1.34 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function limitResult( $sql, $limit, $offset = false );
/**
* LIKE statement wrapper
*
* This takes a variable-length argument list with parts of pattern to match
* containing either string literals that will be escaped or tokens returned by
* {@link anyChar()} or {@link anyString()}.
* Alternatively, the function could be provided with an array of the aforementioned parameters.
*
* Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns
* a LIKE clause that searches for subpages of 'My page title'.
* Alternatively:
* $pattern = [ 'My_page_title/', $dbr->anyString() ];
* $query .= $dbr->buildLike( $pattern );
*
* @since 1.16 in IDatabase, moved to ISQLPlatform in 1.39
* @param array[]|string|LikeMatch $param
* @param-taint $param escapes_sql
* @param string|LikeMatch ...$params
* @param-taint ...$params escapes_sql
* @return string Fully built LIKE statement
* @return-taint none
*/
public function buildLike( $param, ...$params );
/**
* Returns a token for {@link buildLike()} that denotes a '_' to be used in a LIKE query
*
* @return LikeMatch
*/
public function anyChar();
/**
* Returns a token for {@link buildLike()} that denotes a '%' to be used in a LIKE query
*
* @return LikeMatch
*/
public function anyString();
/**
* Determine if the RDBMS supports ORDER BY and LIMIT for separate subqueries within UNION
*
* @return bool
*/
public function unionSupportsOrderAndLimit();
/**
* Construct a UNION query
*
* This is used for providing overload point for other DB abstractions
* not compatible with the MySQL syntax.
*
* @internal callers outside of rdbms library should use UnionQueryBuilder instead.
*
* @param array $sqls SQL statements to combine
* @param bool $all Either {@link IDatabase::UNION_ALL} or {@link IDatabase::UNION_DISTINCT}
* @param array $options Query options
*
* @return string SQL fragment
*/
public function unionQueries( $sqls, $all, $options = [] );
/**
* Convert a timestamp in one of the formats accepted by {@link ConvertibleTimestamp}
* to the format used for inserting into timestamp fields in this DBMS
*
* The result is unquoted, and needs to be passed through addQuotes()
* before it can be included in raw SQL.
*
* @param string|int $ts
*
* @return string
*/
public function timestamp( $ts = 0 );
/**
* Convert a timestamp in one of the formats accepted by ConvertibleTimestamp
* to the format used for inserting into timestamp fields in this DBMS
*
* If NULL is input, it is passed through, allowing NULL values to be inserted
* into timestamp fields.
*
* The result is unquoted, and needs to be passed through addQuotes()
* before it can be included in raw SQL.
*
* @param string|int|null $ts
*
* @return string|null
*/
public function timestampOrNull( $ts = null );
/**
* Find out when 'infinity' is. Most DBMSes support this. This is a special
* keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
* because "i" sorts after all numbers.
*
* @return string
*/
public function getInfinity();
/**
* Encode an expiry time into the DBMS dependent format
*
* @param string $expiry Timestamp for expiry, or the 'infinity' string
* @return string
*/
public function encodeExpiry( $expiry );
/**
* Decode an expiry time into a DBMS independent format
*
* @param string $expiry DB timestamp field value for expiry
* @param int $format TS_* constant, defaults to TS_MW
* @return string
*/
public function decodeExpiry( $expiry, $format = TS_MW );
/**
* Returns an SQL expression for a simple conditional
*
* This doesn't need to be overridden unless CASE isn't supported in the RDBMS.
*
* @param string|array $cond SQL condition expression (yields a boolean)
* @param string $caseTrueExpression SQL expression to return when the condition is true
* @param string $caseFalseExpression SQL expression to return when the condition is false
* @return string SQL fragment
*/
public function conditional( $cond, $caseTrueExpression, $caseFalseExpression );
/**
* Returns a SQL expression for simple string replacement (e.g. REPLACE() in mysql)
*
* @param string $orig Column to modify
* @param string $old Column to seek
* @param string $new Column to replace with
* @return string
*/
public function strreplace( $orig, $old, $new );
/**
* Build a SUBSTRING function
*
* Behavior for non-ASCII values is undefined.
*
* @param string $input Field name
* @param int $startPosition Positive integer
* @param int|null $length Non-negative integer length or null for no limit
* @throws \InvalidArgumentException
* @return string SQL text
* @since 1.31 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function buildSubString( $input, $startPosition, $length = null );
/**
* @param string $field Field or column to cast
* @return string
* @since 1.28 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function buildStringCast( $field );
/**
* @param string $field Field or column to cast
* @return string
* @since 1.31 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function buildIntegerCast( $field );
/**
* Returns true if this database does an implicit order by when the column has an index
* For example: SELECT page_title FROM page LIMIT 1
*
* @return bool
*/
public function implicitOrderby();
/**
* Make certain table names use their own database, schema, and table prefix
* when passed into SQL queries pre-escaped and without a qualified database name
*
* For example, "user" can be converted to "myschema.mydbname.user" for convenience.
* Appearances like `user`, somedb.user, somedb.someschema.user will used literally.
*
* Calling this twice will completely clear any old table aliases. Also, note that
* callers are responsible for making sure the schemas and databases actually exist.
*
* @param array[] $aliases Map of (table => (dbname, schema, prefix) map)
* @since 1.28 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function setTableAliases( array $aliases );
/**
* Convert certain index names to alternative names before querying the DB
*
* Note that this applies to indexes regardless of the table they belong to.
*
* This can be employed when an index was renamed X => Y in code, but the new Y-named
* indexes were not yet built on all DBs. After all the Y-named ones are added by the DBA,
* the aliases can be removed, and then the old X-named indexes dropped.
*
* @param string[] $aliases
* @since 1.31 in IDatabase, moved to ISQLPlatform in 1.39
*/
public function setIndexAliases( array $aliases );
/**
* Return current table aliases.
*
* @internal only to be used inside rdbms library
*/
public function getTableAliases();
/**
* Take the same arguments as IDatabase::select() and return the SQL it would use
*
* This can be useful for making UNION queries, where the SQL text of each query
* is needed. In general, however, callers outside of Database classes should just
* use select().
*
* @see IDatabase::select()
*
* @param string|array $table Table name(s)
* @param-taint $table exec_sql
* @param string|array $vars Field names
* @param-taint $vars exec_sql
* @param string|array $conds Conditions
* @param-taint $conds exec_sql_numkey
* @param string $fname Caller function name
* @param-taint $fname exec_sql
* @param string|array $options Query options
* @param-taint $options none This is special-cased in MediaWikiSecurityCheckPlugin
* @param string|array $join_conds Join conditions
* @param-taint $join_conds none This is special-cased in MediaWikiSecurityCheckPlugin
* @return string SQL query string
* @return-taint onlysafefor_sql
*/
public function selectSQLText(
$table,
$vars,
$conds = '',
$fname = __METHOD__,
$options = [],
$join_conds = []
);
/**
* Format a table name ready for use in constructing an SQL query
*
* This does two important things: it quotes the table names to clean them up,
* and it adds a table prefix if only given a table name with no quotes.
*
* All functions of this object which require a table name call this function
* themselves. Pass the canonical name to such functions. This is only needed
* when calling {@link query()} directly.
*
* @note This function does not sanitize user input. It is not safe to use
* this function to escape user input.
* @param string $name Database table name
* @param string $format One of:
* quoted - Automatically pass the table name through addIdentifierQuotes()
* so that it can be used in a query.
* raw - Do not add identifier quotes to the table name
* @return string Full database name
*/
public function tableName( $name, $format = 'quoted' );
/**
* Fetch a number of table names into an associative array
*
* Much like {@link tableName()}, this is only needed when calling
* {@link query()} directly. Prefer calling other methods,
* or using {@link SelectQueryBuilder}.
*
* Theoretical example (which really does not require raw SQL):
* ```
* [ 'user' => $user, 'watchlist' => $watchlist ] =
* $dbr->tableNames( 'user', 'watchlist' );
* $sql = "SELECT wl_namespace, wl_title FROM $watchlist, $user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
* ```
*
* @param string ...$tables
* @return array
* @deprecated since 1.39; if you must format table names,
* write several calls to {@link tableName} or use {@link tableNamesN}
* instead of calling this function.
*/
public function tableNames( ...$tables );
/**
* Fetch a number of table names into a zero-indexed numerical array
*
* Much like {@link tableName()}, this is only needed when calling
* {@link query()} directly. It is slightly more convenient than
* {@link tableNames()}, but you should still prefer calling other
* methods, or using {@link SelectQueryBuilder}.
*
* Theoretical example (which really does not require raw SQL):
* ```
* [ $user, $watchlist ] = $dbr->tableNamesN( 'user', 'watchlist' );
* $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
* ```
*
* @param string ...$tables
* @return array
*/
public function tableNamesN( ...$tables );
/**
* Build a GROUP_CONCAT or equivalent statement for a query.
*
* This is useful for combining a field for several rows into a single string.
* NULL values will not appear in the output, duplicated values will appear,
* and the resulting delimiter-separated values have no defined sort order.
* Code using the results may need to use the PHP unique() or sort() methods.
*
* @param string $delim Glue to bind the results together
* @param string|array $table Table name
* @param string $field Field name
* @param string|array $conds Conditions
* @param string|array $join_conds Join conditions
* @return string SQL text
* @since 1.23
*/
public function buildGroupConcatField(
$delim, $table, $field, $conds = '', $join_conds = []
);
/**
* Equivalent to IDatabase::selectSQLText() except wraps the result in Subquery
*
* @see IDatabase::selectSQLText()
*
* @param string|array $table Table name
* @param string|array $vars Field names
* @param string|array $conds Conditions
* @param string $fname Caller function name
* @param string|array $options Query options
* @param string|array $join_conds Join conditions
* @return Subquery
* @since 1.31
*/
public function buildSelectSubquery(
$table,
$vars,
$conds = '',
$fname = __METHOD__,
$options = [],
$join_conds = []
);
/**
* Build a reference to a column value from the conflicting proposed upsert() row.
*
* The reference comes in the form of an alias, function, or parenthesized SQL expression.
* It can be used in upsert() SET expressions to handle the merging of column values between
* each conflicting pair of existing and proposed rows. Such proposed rows are said to have
* been "excluded" from insertion in favor of updating the existing row.
*
* This is useful for multi-row upserts() since the proposed values cannot just be included
* as literals in the SET expressions.
*
* @see IDatabase::upsert()
*
* @param string $column Column name
* @return string SQL expression returning a scalar
* @since 1.39
*/
public function buildExcludedValue( $column );
/**
* Set schema variables to be used when streaming commands from SQL files or stdin
*
* Variables appear as SQL comments and are substituted by their corresponding values
*
* @param array|null $vars Map of (variable => value) or null to use the defaults
*/
public function setSchemaVars( $vars );
}