v^@sdZddlmZmZGdddeZGdddeZGdddeZGd d d eZGd d d eZd S)z;Database functions that do comparisons or type conversions.)FuncValuecspeZdZdZdZdZfddZfddZfdd Zd d Z d d Z S)Castz)Coerce an expression to a new field type.ZCASTz,%(function)s(%(expressions)s AS %(db_type)s)cstj|d|dS)N output_field)super__init__)self expressionr) __class__G/tmp/pip-build-8lau8j11/django/django/db/models/functions/comparison.pyr sz Cast.__init__c s,|jj||dtimedatetime)rr rrinsert) rrrrr rZsqlparams format_string)r r r as_sqlites $  zCast.as_sqlitecKs:|jjdkrdnd}|j||d||S)NZ FloatFieldz(%(expressions)s + 0.0)r)rget_internal_typer)rrrrrr r r as_mysqls!z Cast.as_mysqlcKs|j||dd|S)Nrz(%(expressions)s)::%(db_type)s)r)rrrrr r r as_postgresql$szCast.as_postgresql) __name__ __module__ __qualname____doc__functionrrrrrrr r )r r rs  rcs@eZdZdZdZfddZfddZS)Coalescez:Return, from left to right, the first non-null expression.ZCOALESCEcs5t|dkrtdtj||dS)Nz+Coalesce must take at least two expressions)len ValueErrorrr)r expressionsextra)r r r r/s zCoalesce.__init__c sp|jjdkr]|j}|jdd|jDtt|j|||S|j|||S)NZ TextFieldcSs"g|]}t|ddqS)r#ZTO_NCLOB)r).0r r r r :s z&Coalesce.as_oracle..)rrcopyZset_source_expressionsget_source_expressionsrr$r)rrrrclone)r r r as_oracle4s  zCoalesce.as_oracle)rr r!r"r#rr/r r )r r r$+s r$cs@eZdZdZdZfddZfddZS)Greatestz Return the maximum expression. If any expression is null the return value is database-specific: On PostgreSQL, the maximum not-null expression is returned. On MySQL, Oracle, and SQLite, if any expression is null, null is returned. ZGREATESTcs5t|dkrtdtj||dS)Nr%z+Greatest must take at least two expressions)r&r'rr)rr(r))r r r rJs zGreatest.__init__c stj||dd|S)zUse the MAX function on SQLite.r#MAX)rr)rrrr)r r r rOszGreatest.as_sqlite)rr r!r"r#rrr r )r r r0@s r0cs@eZdZdZdZfddZfddZS)Leastz Return the minimum expression. If any expression is null the return value is database-specific: On PostgreSQL, return the minimum not-null expression. On MySQL, Oracle, and SQLite, if any expression is null, return null. ZLEASTcs5t|dkrtdtj||dS)Nr%z(Least must take at least two expressions)r&r'rr)rr(r))r r r r^s zLeast.__init__c stj||dd|S)zUse the MIN function on SQLite.r#ZMIN)rr)rrrr)r r r rcszLeast.as_sqlite)rr r!r"r#rrr r )r r r2Ts r2cs.eZdZdZdZfddZS)NullIfZNULLIFr%c sP|jd}t|tr:|jdkr:tdtj|||S)Nrz2Oracle does not allow Value(None) for expression1.)r- isinstancervaluer'rr)rrrrZ expression1)r r r r/ls zNullIf.as_oracle)rr r!r#arityr/r r )r r r3hs r3N) r"Zdjango.db.models.expressionsrrrr$r0r2r3r r r r s &