You can also chain withKeyName() to override default key name that is generated from table and column names (result is identical to specifying second parameter to function foreign()).ĭeferrable foreign constraint is supported on Postgres and Oracle and can be set by chaining. You can also chain onDelete() and/or onUpdate() to set the reference option (RESTRICT, CASCADE, SET NULL, NO ACTION) for the operation. Table.foreign(columns, )Īdds a foreign key constraint to a table for an existing column using table.foreign(column).references(column) or multiple columns using table.foreign(columns).references(columns).inTable(table).Ī default key name using the columns is used unless foreignKeyName is specified. ROWID (by whatever name you call it) is assigned a value whenever you INSERT a row, as you would expect. If you include a column of type INTEGER PRIMARY KEY, that column points at (is an alias for) the automatic ROWID column. This is in every SQLite table whether you ask for it or not. If you want to chain unique() while creating new column you can use unique foreign # 9 Answers Sorted by: 219 You get one for free, called ROWID. In PostgreSQL, SQLite and MSSQL a partial unique index can be specified by setting a 'where' predicate. In MSSQL and Postgres, you can set the useConstraint option to true to create a unique constraint instead of a unique index (defaults to false for MSSQL, true for Postgres without predicate, false for Postgres with predicate). Deferrable unique constraint are supported on Postgres and Oracle and can be set by passing deferrable option to options object. If you need to create a composite index, pass an array of column to columns. A default index name using the columns is used unless indexName is specified. SQLites metadata does not tell linq2db that these special primary keys might be nullable, nor does it flag them with 'autoincrement'. In MySQL, the storage engine index type may be 'btree' or 'hash' index types, more info in Index Options section. Table.increments(name, options=)Īdds an unique index to a table over the given columns. Renames a column from one name to another. dropSchemaIfExists ( 'public', true ) Schema Building # dropColumn #ĭrops a column, specified by the column's name dropColumns #ĭrops multiple columns, taking a variable number of column names. PostgreSQL, Oracle, or SQL Server, or as a special case when using SQLite with the pysqlite driver and a single auto-increment column, a SQL expression may be assigned to a primary key column as well. dropSchemaIfExists ( 'public' ) //drop schema if exists 'public' cascade SQLite has an interesting way of handling auto-increment columns.
0 Comments
Leave a Reply. |