PostgreSQL.Statement

Tools to deal with templates and statements are defined here.

Documentation

data Template a

SQL statement template

Since: 0.0.0

Instances

Contravariant Template

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

contramap :: (a -> b) -> Template b -> Template a

(>$) :: b -> Template b -> Template a

(HasField n r a, Param a) => IsLabel n (Template r)

OverloadedLabels helper for param

#myParam === param (getField @"myParam")

Use this with a database:

data MyFoo = MyFoo { bar :: Int, baz :: String }

myStatementTpl :: Template MyFoo
myStatementTpl = "SELECT * FROM my_foo WHERE bar = " <> #bar <> " AND baz = " <> #baz

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

fromLabel :: Template r

IsString (Template a)

OverloadedStrings helper for code

"my code" === code "my code"

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

fromString :: String -> Template a

Semigroup (Template a)

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

(<>) :: Template a -> Template a -> Template a

sconcat :: NonEmpty (Template a) -> Template a

stimes :: Integral b => b -> Template a -> Template a

Monoid (Template a)

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

mempty :: Template a

mappend :: Template a -> Template a -> Template a

mconcat :: [Template a] -> Template a

code :: Text -> Template a

Create a code-only statement.

Since: 0.0.0

identifier :: Text -> Template a

Create a code segment that mentions the given identifier (e.g. table or column name).

Since: 0.0.0

string :: Text -> Template a

Encase the given string literal in single quotes. Single quotes in the literal are automatically escaped.

Since: 0.0.0

param :: forall b a. Param b => (a -> b) -> Template a

Reference a parameter.

Since: 0.0.0

paramWith :: Info (a -> Value) -> Template a

Reference a parameter.

Since: 0.0.0

constant :: forall b a. Param b => b -> Template a

Constant part of a query.

Since: 0.0.0

data Statement a

Rendered SQL statement

Since: 0.0.0

Constructors

Statement

Fields

• statement_code :: ByteString
• statement_mkParams :: a -> [PackedParam]
• statement_types :: [Oid]
• statement_name :: ByteString

Instances

Contravariant Statement

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

contramap :: (a -> b) -> Statement b -> Statement a

(>$) :: b -> Statement b -> Statement a

Executable Statement

Since: 0.0.0

Defined in PostgreSQL.Query.Class

Methods

execute :: Query query => Statement param -> param -> query (NativeResult query)

renderTemplate :: Template a -> Statement a

Render the SQL statement.

Since: 0.0.0

data PreparedStatement a

Prepared statement

Since: 0.0.0

Constructors

PreparedStatement

Fields

• preparedStatement_name :: ByteString
• preparedStatement_mkParams :: a -> [PackedParamPrepared]

Instances

Contravariant PreparedStatement

Since: 0.0.0

Defined in PostgreSQL.Statement

Methods

contramap :: (a -> b) -> PreparedStatement b -> PreparedStatement a

(>$) :: b -> PreparedStatement b -> PreparedStatement a

Executable PreparedStatement

Since: 0.0.0

Defined in PostgreSQL.Query.Class

Methods

execute :: Query query => PreparedStatement param -> param -> query (NativeResult query)

tpl :: QuasiQuoter

Produces a Template expression.

Supports the same features as stmt.

Since: 0.0.0

stmt :: QuasiQuoter

Produces a Statement expression.

[stmt| SELECT $param * 2 |]

Use $$ to render a single $.

Parameters

Use $param or ${param} to reference a query parameter.

[stmt| ${x} |] is equivalent to param x.

Substitutions

Use $(substr) to embed another Template where substr :: Template a.

[stmt| $(x) |] is equivalent to x.

Examples

data MyParams = MyParams { foo :: Int, bar :: Text }

myStatement :: Statement MyParams
myStatement = [stmt| SELECT baz FROM my_table WHERE foo > ${foo} AND bar = ${bar} |]

Since: 0.0.0