Carray($PTR,$N) is a table-valued function with a single column (named "value") and zero or more rows. The "value" of each row in the carray() is taken from a C-language array that is $N elements long. $PTR is a pointer to the beginning of the array. In this way, the carray() function provides a convenient mechanism to bind C-language arrays to SQL queries.
The carray() function takes two or three arguments. The first argument is a pointer to an array. Since pointer values cannot be specified directly in SQL, the first argument must be a parameter that is bound to a pointer value using the sqlite3_bind_pointer() interface using a pointer-type of "carray". The second argument is the number of elements in the array. The optional third argument is a string that determines the datatype of the elements in the C-language array. Allowed values for the third argument are:
The default datatype is 'int32'.
The carray() function can be used in the FROM clause of a query. For example, to query two entries from the OBJ table using rowids taken from a C-language array at address $PTR.
SELECT obj.* FROM obj, carray($PTR, 10) AS x WHERE obj.rowid=x.value;
This query gives the same result:
SELECT * FROM obj WHERE rowid IN carray($PTR, 10);
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