- Documentation
- Reference manual
- Packages
- Constraint Query Language A high level interface to SQL databases
- library(cql/cql): CQL - Constraint Query Language
- Examples
- Simple INSERT
- Simple INSERT with retrieval of identity of the inserted
- Simple DELETE
- Simple SELECT
- Simple UPDATE
- WHERE with arithmetic comparison
- Simple INNER JOIN
- Arithmetic UPDATE with an INNER JOIN and a WHERE restriction
- Confirm row does not exist
- Aggregation - Count
- Aggregation - Sum
- Aggregation - Average
- Maximum Value
- Minimum Value
- Aggregation requiring GROUP BY
- INNER JOIN with an aggregation sub-query where the sub-query is constrained by a shared variable from the main query
- INNER JOIN in an aggregation sub-query
- Negation
- EXISTS
- Left Outer Join
- List-based Restrictions
- Compile time in-list constraint
- Disjunction resulting in OR in WHERE clause
- Disjunction resulting in different joins (implemented as a SQL UNION)
- Disjunction resulting in different SELECT attributes (implemented as separate ODBC queries)
- ORDER BY
- DISTINCT
- SELECT with NOT NULL restriction
- First N
- Self JOIN
- Removing null comparisions
- Three table JOIN
- Three table JOIN with NOLOCK locking hint
- SELECT with LIKE
- Writing exceptions directly to the database
- TOP N is Parametric
- Using compile_time_goal/1
- ON
- Expressions In Where Restrictions
- Explicitly avoid the "No WHERE restriction" message
- HAVING
- INSERT and UPDATE value in-line formatting
- Negations in WHERE Clauses
- Predicate-generated Attribute Values
- INSERT from SELECT
- Examples
- library(cql/cql): CQL - Constraint Query Language
- Constraint Query Language A high level interface to SQL databases
1.7.16 INNER JOIN with an aggregation sub-query where the sub-query is constrained by a shared variable from the main query
{[],
se_lt_x :: [b-J1, a-A]
=*=
se_lt_z :: [h-J1, i-I, g-Z],
I > min(Y, se_lt_y :: [f-Y, d-Z])}
The main query and the sub-query share variable Z. The generated SQL is:
SELECT x37.a, z4.i, z4.g FROM se_lt_x x37 INNER JOIN se_lt_z z4 ON x37.b=z4.h and z4.h=x37.b WHERE z4.i > (SELECT min(y11.f) FROM se_lt_y y11 WHERE z4.g=y11.d)