CTAGS-LANG-SQL(7)

NAME
ctags-lang-sql - The man page of the SQL parser for Universal Ctags

SYNOPSIS
ctags ... [--extras={guest}] --languages=+SQL ...

DESCRIPTION

The SQL parser supports various SQL dialects. PostgreSQL is one of them.

PostgreSQL allows user-defined functions to be written in other languages (procedural languages) besides SQL and C [PL].

The SQL parser makes tags for language objects in the user-defined functions written in the procedural languages if the guest extra is enabled.

The SQL parser looks for a token coming after LANGUAGE keyword in the source code to choose a proper guest parser.

... LANGUAGE plpythonu AS '... user-defined function ' ...
... AS $$ user-defined function $$ LANGUAGE plv8 ...

In the above examples, plpythonu and plv8 are the names of procedural languages. The SQL parser trims pl at the start and u at the end of the name before finding a ctags parser. For plpythonu and plv8, the SQL parser extracts python and v8 as the candidates of guest parsers.

For plpythonu, ctags can run its Python parser. ctags doesn't have a parser named v8. However, the JavaScript parser in ctags has v8 as an alias. So ctags can run the JavaScript parser as the guest parser for plv8.

EXAMPLES

tagging code including a user-defined function in a string literal [GH3006]:

"input.sql"

CREATE OR REPLACE FUNCTION fun1() RETURNS VARCHAR AS '
DECLARE
        test1_var1 VARCHAR(64) := $$ABC$$;
        test1_var2 VARCHAR(64) := $xyz$XYZ$xyz$;
        test1_var3     INTEGER := 1;
BEGIN
        RETURN  TO_CHAR(test_var3, ''000'') || test1_var1 || test1_var2;
END;
' LANGUAGE plpgsql;

"output.tags" with "--options=NONE -o - --sort=no --extras=+{guest} input.sql"

fun1    input.sql       /^CREATE OR REPLACE FUNCTION fun1() RETURNS VARCHAR AS '$/;"    f
test1_var1      input.sql       /^      test1_var1 VARCHAR(64) := $$ABC$$;$/;"  v
test1_var2      input.sql       /^      test1_var2 VARCHAR(64) := $xyz$XYZ$xyz$;$/;"    v
test1_var3      input.sql       /^      test1_var3     INTEGER := 1;$/;"        v

tagging code including a user-defined function in a dollar quote [GH3006]:

"input.sql"

CREATE OR REPLACE FUNCTION fun2() RETURNS VARCHAR LANGUAGE plpgsql AS $$
DECLARE
        test2_var1 VARCHAR(64) := 'ABC2';
        test2_var2 VARCHAR(64) := 'XYZ2';
        test2_var3        INTEGER := 2;
BEGIN
        RETURN  TO_CHAR(test2_var3, '000') || test2_var1 || test2_var2;
END;
$$;

"output.tags" with "--options=NONE -o - --sort=no --extras=+{guest} input.sql"

fun2    input.sql       /^CREATE OR REPLACE FUNCTION fun2() RETURNS VARCHAR LANGUAGE plpgsql AS $\$$/;" f
test2_var1      input.sql       /^      test2_var1 VARCHAR(64) := 'ABC2';$/;"   v
test2_var2      input.sql       /^      test2_var2 VARCHAR(64) := 'XYZ2';$/;"   v
test2_var3      input.sql       /^      test2_var3        INTEGER := 2;$/;"     v

tagging code including a user-defined written in JavaScript:

-- Derived from https://github.com/plv8/plv8/blob/r3.0alpha/sql/plv8.sql
CREATE FUNCTION test(keys text[], vals text[]) RETURNS text AS
$$
        var o = {};
        for (var i = 0; i < keys.length; i++)
                o[keys[i]] = vals[i];
        return JSON.stringify(o);
$$
LANGUAGE plv8 IMMUTABLE STRICT;

"output.tags" with "--options=NONE -o - --sort=no --extras=+{guest} input.sql"

test    input.sql       /^CREATE FUNCTION test(keys text[], vals text[]) RETURNS text AS$/;"    f
o       input.sql       /^      var o = {};$/;" v

KNOWN BUGS

Escape sequences ('') in a string literal may make a guest parser confused.

SEE ALSO

ctags(1), ctags-client-tools(7)

REFERENCES

[PL]
    PostgreSQL 9.5.25 Documentation, "Chapter 39. Procedural Languages", https://www.postgresql.org/docs/9.5/xplang.html

[GH3006]
    @bagl's comment submitted to https://github.com/universal-ctags/ctags/issues/3006