Selectors contain the target fields or expressions in a SQL SELECT statement, and perform the conversion to haskell. Selectors are instances of Applicative, so they can return the desired haskell type.

combinator for aliasing columns.

The polymorphic selector. The return type is determined by type inference.

an integer field (TINYINT.. BIGINT). Any bounded haskell integer type can be used here , for example Int, Int32, Word32. An Overflow ur Underflow error will be raised if the value doesn't fit the type.

Un unbounded integer field, either a bounded integer (TINYINT, etc...) or DECIMAL in the database. Will throw a type error if the stored value is actually fractional.

WARNING: this function could potentially create huge integers with DECIMAL, if the exponent is large, even fillup the space and crash your program! Only use this on trusted inputs, or use Scientific instead.

a DOUBLE field.

a FLOAT field.

A DECIMAL or NUMERIC field.

a DATETIME or a TIMESTAMP field.

A TIME field taken as a specific time.

a TIME field taken as a time duration.

A DATE field.

A binary BLOB field.

a TEXT field.

Read the columns directly as a MySQLValue type without conversion.

Ignore the content of the given columns

An Insertor a provides a mapping of parts of values of type a to columns in the database. Insertors can be combined using <>.

into uses the given extractor function to map the part to a field. For example:

insertValues "Person" (fst `into` "name" <> snd `into` "age")
  [("Bart Simpson", 10), ("Lisa Simpson", 8)]

lensInto uses a lens to map the part to a field. For example:

insertValues "Person" (_1 `lensInto` "name" <> _2 `lensInto` "age")
  [("Bart Simpson", 10), ("Lisa Simpson", 8)]

insert a single value directly

insert the values of a tuple