diff options
| -rw-r--r-- | doc/src/sgml/information_schema.sgml | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/doc/src/sgml/information_schema.sgml b/doc/src/sgml/information_schema.sgml index d57a1323409..9c39e9aab50 100644 --- a/doc/src/sgml/information_schema.sgml +++ b/doc/src/sgml/information_schema.sgml @@ -917,6 +917,13 @@ domain is the owner of the constraint.) </para> + <para> + The SQL standard considers not-null constraints to be check constraints + with a <literal>CHECK (<replaceable>column_name</replaceable> IS NOT + NULL)</literal> expression. So not-null constraints are also included here + and don't have a separate view. + </para> + <table> <title><structname>check_constraints</structname> Columns</title> <tgroup cols="1"> @@ -2116,7 +2123,9 @@ columns in the current database that are used by some constraint. Only those columns are shown that are contained in a table owned by a currently enabled role. For a check constraint, this view - identifies the columns that are used in the check expression. For + identifies the columns that are used in the check expression. For a + not-null constraint, this view identifies the column that the constraint is + defined on. For a foreign key constraint, this view identifies the columns that the foreign key references. For a unique or primary key constraint, this view identifies the constrained columns. @@ -6856,7 +6865,7 @@ ORDER BY c.ordinal_position; <structfield>constraint_type</structfield> <type>character_data</type> </para> <para> - Type of the constraint: <literal>CHECK</literal>, + Type of the constraint: <literal>CHECK</literal> (includes not-null constraints), <literal>FOREIGN KEY</literal>, <literal>PRIMARY KEY</literal>, or <literal>UNIQUE</literal> </para></entry> |