Opaleye.Operators

Keep only the rows of a query satisfying a given condition, using an SQL WHERE clause. It is equivalent to the Haskell function

where_ :: Bool -> [()]
where_ True  = [()]
where_ False = []

You would typically use restrict if you want to write your query using Arrow notation. If you want to use monadic style then where_ will suit you better.

Add a WHERE EXISTS clause to the current query.

Add a WHERE NOT EXISTS clause to the current query.

Fractional division.

Conversion from an Integer. An integer literal represents the application of the function fromInteger to the appropriate value of type Integer, so such literals have type (Num a) => a.

Absolute value.

Unary negation.

Sign of a number. The functions abs and signum should satisfy the law:

abs x * signum x == x

For real numbers, the signum is either -1 (negative), 0 (zero) or 1 (positive).

A polymorphic equality operator that works for all types that you have run makeAdaptorAndInstanceInferrable on. This may be unified with .== in a future version.

A polymorphic inequality operator that works for all types that you have run makeAdaptorAndInstanceInferrable on. This may be unified with ./= in a future version.

Integral division, named after quot. It maps to the / operator in Postgres.

The remainder of integral division, named after rem. It maps to MOD (%) in Postgres, confusingly described as "modulo (remainder)".

Select the first case for which the condition is true.

Monomorphic if/then/else.

This may be replaced by ifThenElseMany in a future version.

Polymorphic if/then/else.

Boolean or

Boolean and

Boolean not

True when any element of the container is true

Concatenate Field SqlText

To lowercase

To uppercase

Postgres LIKE operator

Postgres ILIKE operator

in_ is designed to be used in prefix form.

in_ validUsers user checks whether user is a valid user. in_ validUsers is a function which checks whether a user is a valid user.

inMany is a generalization of in_ to values with multiple fields. It is designed to be used in prefix form.

inMany validUsers user checks whether user is a valid user. inMany validUsers is a function which checks whether a user is a valid user.

True if the first argument occurs amongst the rows of the second, false otherwise.

This operation is equivalent to Postgres's IN operator.

Class of Postgres types that represent json values. Used to overload functions and operators that work on both SqlJson and SqlJsonb.

Warning: making additional instances of this class can lead to broken code!

Class of Postgres types that can be used to index json values.

Warning: making additional instances of this class can lead to broken code!

Use SqlJsonIndex instead. Will be deprecated in a future version.

Get JSON object field by key.

Get JSON object field as text.

Get JSON object at specified path.

Get JSON object at specified path as text.

Does the left JSON value contain within it the right value?

Is the left JSON value contained within the right value?

Does the key/element string exist within the JSON value?

Do any of these key/element strings exist?

Do all of these key/element strings exist?

Create an SqlJson object from a collection of fields.

Note: This is implemented as a variadic function in postgres, and as such, is limited to 50 arguments, or 25 key-value pairs.

Given a label and a field, generates a pair for use with jsonBuildObject

Combine JSONBuildObjectFields using (<>)

Append two SqlArrays

Prepend an element to a SqlArray

Remove all instances of an element from a SqlArray

Remove all NULL values from a SqlArray

Postgres's array_position

Whether the element (needle) exists in the array (haystack). N.B. this is implemented hackily using array_position. If you want the equivalent implemented using = any then use sqlElemAny.

Whether the element (needle) exists in the array (haystack). This is implemented using = any.

Access the upper bound of a range. For discrete range types it is the exclusive bound.

Access the lower bound of a range. For discrete range types it is the inclusive bound.

Current date and time (start of current transaction)

IntervalNum from to determines from which date or time types an interval can be added (addInterval) or subtracted (minusInterval) and which is the resulting type.

The instances should correspond to the interval + and - operations listed in:

https://www.postgresql.org/docs/current/functions-datetime.html#OPERATORS-DATETIME-TABLE