You can specify the table(s) being selected from in either a string or an array. The from() method specifies the FROM fragment of a SQL statement. You can call addSelect() to select additional columns. To select distinct rows, you may call distinct(), like the following: // SELECT DISTINCT `user_id`. SELECT `id`, (SELECT COUNT(*) FROM `user`) AS `count` FROM `post` For example, $subQuery = ( new Query())->select( 'COUNT(*)')->from( 'user') You should specify each sub-query in terms ofĪ yii\db\Query object. Starting from version 2.0.1, you may also select sub-queries. For example, $query->select() Īs with all places where raw SQL is involved, you may use the DBMS agnostic quoting syntaxįor table and column names when writing DB expressions in select.
That contains commas to avoid incorrect automatic name quoting.
You must use the array format when selecting a DB expression If you do not call the select() method when building a query, * will be selected, whichīesides column names, you can also select DB expressions.
Json query builder online code#
If you are using the array format to specify columns, you can also use the array keys to specify the column aliases.įor example, the above code can be rewritten as follows, $query->select()
$query->select( 'user.id AS user_id, email') The column names being selected may include table prefixes and/or column aliases, like you do when writing raw SQL queries.įor example, $query->select() The column names being selected willīe automatically quoted when the SQL statement is being generated from a query object. You can specifyĬolumns to be selected in either an array or a string, like the following. The select() method specifies the SELECT fragment of a SQL statement. In the following, we will describe the usage of each query building method. For example, to specify the FROM part of a SQL query, you would call the from() method.Īll the query building methods return the query object itself, which allows you to chain multiple calls together. The names of these methods resemble the SQL keywords used in the corresponding parts of the SQL To build a yii\db\Query object, you call different query building methods to specify different parts ofĪ SQL query. quoting table/column names differently) from DBMS-independent yii\db\QueryBuilder is the class responsibleįor generating DBMS-dependent SQL statements (e.g. The latter is invokedīy the former implicitly when you call one of the query methods. Info: You usually mainly work with yii\db\Query instead of yii\db\QueryBuilder. SELECT `id`, `email` FROM `user` WHERE `last_name` = :last_name The above code generates and executes the following SQL query, where the :last_name parameter is bound with the The following code shows a typical way of using query builder: $rows = ( new \yii\db\Query()) all()) of yii\db\Query to retrieve data from the database.
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