Safe Haskell	Safe-Inferred
Language	GHC2021

Database.Persist.Sql.Lifted.Expression.String

Synopsis

lower_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s)
upper_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s)
trim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s)
ltrim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s)
rtrim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s)
length_ :: (SqlString s, Num a) => SqlExpr (Value s) -> SqlExpr (Value a)
left_ :: (SqlString s, Num a) => (SqlExpr (Value s), SqlExpr (Value a)) -> SqlExpr (Value s)
right_ :: (SqlString s, Num a) => (SqlExpr (Value s), SqlExpr (Value a)) -> SqlExpr (Value s)
like :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value Bool)
ilike :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value Bool)
(%) :: SqlString s => SqlExpr (Value s)
concat_ :: SqlString s => [SqlExpr (Value s)] -> SqlExpr (Value s)
(++.) :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value s)
castString :: (SqlString s, SqlString r) => SqlExpr (Value s) -> SqlExpr (Value r)

Documentation

lower_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) #

LOWER function.

upper_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) #

UPPER function. @since 3.3.0

trim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) #

TRIM function. @since 3.3.0

ltrim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) #

LTRIM function. @since 3.3.0

rtrim_ :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) #

RTRIM function. @since 3.3.0

length_ :: (SqlString s, Num a) => SqlExpr (Value s) -> SqlExpr (Value a) #

LENGTH function. @since 3.3.0

left_ :: (SqlString s, Num a) => (SqlExpr (Value s), SqlExpr (Value a)) -> SqlExpr (Value s) #

LEFT function. @since 3.3.0

right_ :: (SqlString s, Num a) => (SqlExpr (Value s), SqlExpr (Value a)) -> SqlExpr (Value s) #

RIGHT function. @since 3.3.0

like :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value Bool) infixr 2 #

LIKE operator.

ilike :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value Bool) infixr 2 #

ILIKE operator (case-insensitive LIKE).

Supported by PostgreSQL only. Deprecated in version 3.6.0 in favor of the version available from Database.Esqueleto.PostgreSQL.

Since: esqueleto-2.2.3

(%) :: SqlString s => SqlExpr (Value s) #

The string %. May be useful while using like and concatenation (concat_ or ++., depending on your database). Note that you always have to type the parenthesis, for example:

name `like` (%) ++. val "John" ++. (%)

concat_ :: SqlString s => [SqlExpr (Value s)] -> SqlExpr (Value s) #

The CONCAT function with a variable number of parameters. Supported by MySQL and PostgreSQL. SQLite supports this in versions after 3.44.0, and persistent-sqlite supports this in versions 2.13.3.0 and after.

(++.) :: SqlString s => SqlExpr (Value s) -> SqlExpr (Value s) -> SqlExpr (Value s) infixr 5 #

The || string concatenation operator (named after Haskell's ++ in order to avoid naming clash with ||.).

Supported by SQLite and PostgreSQL.

MySQL support requires setting the SQL mode to PIPES_AS_CONCAT or ANSI - see this StackOverflow answer.

castString :: (SqlString s, SqlString r) => SqlExpr (Value s) -> SqlExpr (Value r) #

Cast a string type into Text. This function is very useful if you want to use newtypes, or if you want to apply functions such as like to strings of different types.

Safety: This is a slightly unsafe function, especially if you have defined your own instances of SqlString. Also, since Maybe is an instance of SqlString, it's possible to turn a nullable value into a non-nullable one. Avoid using this function if possible.