Frames.Joins

Functions for performing SQL style table joins on Frame objects. Uses Data.Discrimination under the hood for O(n) joins. These have behaviour equivalent to INNER JOIN, FULL JOIN, LEFT JOIN, and RIGHT JOIN from SQL.

Documentation

innerJoin

Arguments

:: (fs ⊆ rs, fs ⊆ rs2, rs ⊆ (rs ++ rs2'), rs2' ⊆ rs2, rs2' ~ RDeleteAll fs rs2, Grouping (Record fs), RecVec rs, RecVec rs2', RecVec (rs ++ rs2'))

=> Frame (Record rs)

The left frame

-> Frame (Record rs2)

The right frame

-> Frame (Record (rs ++ rs2'))

The joined frame

Perform an inner join operation on two frames.

Requires the language extension TypeApplications for specifying the columns to join on.

Joins can be done on on one or more columns provided the matched columns have a Grouping instance, most simple types do.

Presently join columns must be present and named identically in both left and right frames.

Basic usage: innerJoin @'[JoinCol1, ..., JoinColN] leftFrame rightFrame

outerJoin

Arguments

:: (fs ⊆ rs, fs ⊆ rs2, rs ⊆ (rs ++ rs2'), rs' ⊆ rs, rs' ~ RDeleteAll fs rs, rs2' ⊆ rs2, rs2' ~ RDeleteAll fs rs2, ors ~ (rs ++ rs2'), ors :~: (rs' ++ rs2), RecApplicative rs2', RecApplicative rs, RecApplicative rs', Grouping (Record fs), RMap rs, RMap rs2, RMap ors, RecVec rs, RecVec rs2', RecVec ors)

=> Frame (Record rs)

The left frame

-> Frame (Record rs2)

The right frame

-> [Rec (Maybe :. ElField) ors]

A list of the merged records, now in the Maybe functor

Perform an outer join (FULL JOIN) operation on two frames.

Requires the use the language extension TypeApplications for specifying the columns to join on.

Joins can be done on on one or more columns provided the columns have a Grouping instance, most simple types do.

Presently join columns must be present and named identically in both left and right frames.

Returns a list of Records in the Maybe interpretation functor. If a key in the left table is missing from the right table, non-key columns from the right table are filled with Nothing. If a key in the right table is missing from the left table, non-key columns from the right table are filled with Nothing.

Basic usage: outerJoin @'[JoinCol1, ..., JoinColN] leftFrame rightFrame

leftJoin

Arguments

:: (fs ⊆ rs, fs ⊆ rs2, rs ⊆ (rs ++ rs2'), rs2' ⊆ rs2, rs2' ~ RDeleteAll fs rs2, RMap rs, RMap (rs ++ rs2'), RecApplicative rs2', Grouping (Record fs), RecVec rs, RecVec rs2', RecVec (rs ++ rs2'))

=> Frame (Record rs)

The left frame

-> Frame (Record rs2)

The right frame

-> [Rec (Maybe :. ElField) (rs ++ rs2')]

A list of the merged records, now in the Maybe functor

Perform an left join operation on two frames.

Requires the language extension TypeApplications for specifying the columns to join on.

Joins can be done on on one or more columns provided the columns have a Grouping instance, most simple types do.

Presently join columns must be present and named identically in both left and right frames.

Returns a list of Records in the Maybe interpretation functor. If a key in the left table is missing from the right table, non-key columns from the right table are filled with Nothing.

Basic usage: leftJoin @'[JoinCol1, ..., JoinColN] leftFrame rightFrame

rightJoin

Arguments

:: (fs ⊆ rs, fs ⊆ rs2, rs ⊆ (rs ++ rs2'), rs' ⊆ rs, rs' ~ RDeleteAll fs rs, rs2' ⊆ rs2, rs2' ~ RDeleteAll fs rs2, ors ~ (rs ++ rs2'), ors :~: (rs' ++ rs2), RecApplicative rs2', RecApplicative rs, RecApplicative rs', Grouping (Record fs), RMap rs2, RMap ors, RecVec rs, RecVec rs2', RecVec ors)

=> Frame (Record rs)

The left frame

-> Frame (Record rs2)

The right frame

-> [Rec (Maybe :. ElField) ors]

A list of the merged records, now in the Maybe functor

Perform an right join operation on two frames.

Requires the language extension TypeApplications for specifying the columns to join on.

Joins can be done on on one or more columns provided the columns have a Grouping instance, most simple types do.

Presently join columns must be present and named identically in both left and right frames.

Returns a list of Records in the Maybe interpretation functor. If a key in the right table is missing from the left table, non-key columns from the right table are filled with Nothing.

Basic usage: rightJoin @'[JoinCol1, ..., JoinColN] leftFrame rightFrame