pglast.printers.sfuncs — Special function printers

The PostgreSQL parser translates some SQL constructs into function calls, for example the expression EXTRACT(YEAR FROM date_column) is represented the same as pg_catalog.date_part('year', date_column).

This module declares some of those equivalences, implementing alternative printers that will be used when the option special_functions of the output stream is set to True.

pglast.printers.sfuncs.btrim(node, output)

Emit function pg_catalog.btrim('  abc  ') as trim(BOTH FROM '  abc  ') and pg_catalog.btrim('xxabcxx', 'x') as trim(BOTH 'x' FROM 'xxabcxx').

pglast.printers.sfuncs.extract(node, output)

Emit function pg_catalog.extract(field, timestamp) as EXTRACT(field FROM timestamp)..

pglast.printers.sfuncs.ltrim(node, output)

Emit function pg_catalog.ltrim('  abc  ') as trim(LEADING FROM '  abc  ') and pg_catalog.ltrim('xxabcxx', 'x') as trim(LEADING 'x' FROM 'xxabcxx').

pglast.printers.sfuncs.normalize(node, output)

Emit function pg_catalog.normalize(a) as normalize(x) and function pg_catalog.normalize('a','b') as normalize('a', b).

pglast.printers.sfuncs.overlaps(node, output)

Emit function pg_catalog.overlaps(a, b, c, d) as (a, b) OVERLAPS (c, d).

pglast.printers.sfuncs.overlay(node, output)

Emit function pg_catalog.overlay('Txxxxas','hom', 2, 4) as overlay('Txxxxas' PLACING 'hom' FROM 2 FOR 4).”

pglast.printers.sfuncs.pg_collation_for(node, output)

Emit function pg_catalog.pg_collation_for(x) as COLLATION FOR (x).

pglast.printers.sfuncs.position(node, output)

Emit function pg_catalog.position('abcd', 'a') as position('a' IN 'abcd').

pglast.printers.sfuncs.rtrim(node, output)

Emit function pg_catalog.rtrim('  abc  ') as trim(TRAILING FROM '  abc  ') and pg_catalog.rtrim('xxabcxx', 'x') as trim(TRAILING 'x' FROM 'xxabcxx')

pglast.printers.sfuncs.substring(node, output)

Emit function pg_catalog.substring('Txxxxas', 2, 4) as substring('Txxxxas' FROM 2 FOR 4) and pg_catalog.substring('blabla', 2) as substring('blabla' FROM 2).

pglast.printers.sfuncs.timezone(node, output)

Emit function pg_catalog.timezone(tz, timestamp) as timestamp AT TIME ZONE tz.

pglast.printers.sfuncs.xmlexists(node, output)

Emit function pg_catalog.xmlexists(x, y) as xmlexists(x PASSING BY REF y).