PostgreSQL Function to dynamically reshape and create tables in loop function - postgresql

Question

I am pretty fresh to PostgreSQL, so please be kind.
I am pretty sure that my problem is that I am mixing plain and dynamic SQL. I have read the relevant documentation but I am not experienced enough to see where I have gone wrong (hoping that my issue is not something more fundamental).
Currently the script is failing with a Query execution error:
SQL Error [42601]: ERROR: syntax error at or near "CREATE"
I intend to use this function to unpivot >9,000 tables (for analysis purposes); fortunately all tables have the same structure.
CREATE OR REPLACE FUNCTION all_schemaTables_unpivot(_schemaName text, _tableName text)
RETURNS void AS
$BODY$
DECLARE
_tbl record;
BEGIN
FOR _tbl IN
SELECT
quote_ident(schemaname) || '.' || quote_ident(tablename) AS fName,
quote_ident(tablename) AS tName
FROM pg_tables
WHERE schemaname = _schemaName
AND tablename LIKE _tableName
LOOP
EXECUTE 'CREATE TABLE ' || _tbl.tName || '_up AS
SELECT region_id, key AS sequential_id, value
FROM (SELECT row_to_json(t.*) AS line, region_id
FROM ' || _tbl.tName || ' AS t) AS r
JOIN LATERAL json_each_text(r.line) ON (key <> "region_id")';
END LOOP;
END;
$BODY$ LANGUAGE plpgsql;
Thanks in advance.

Answer 1

To get the script to work I just needed to fix two things:
I originally did not set appropriate spaces around the query concatenating (thanks #KaushikNayak)
I incorrectly set the quoting values around my dynamic variables (see the 'quote_ident(_tbl.newTableName)' addition. People more expert in PostgreSQL than I will surely have a much cleaner approach - but at least it works!
Moral of the story, sometimes the fix is staring you in the face, but you have been staring at the script for too long! Leave it for awhile and the answer becomes clear.
CREATE OR REPLACE FUNCTION
all_schemaTables_unpivot(_schemaName text, _tableName text)
RETURNS void AS
$BODY$
DECLARE
_tbl record;
BEGIN
FOR _tbl IN
SELECT
quote_ident(schemaname) || '.' || quote_ident(tablename) AS fullNamePath,
quote_ident(tablename) || '_up' AS newTableName
FROM pg_tables
WHERE schemaname = _schemaName
AND tablename LIKE _tableName
LOOP
EXECUTE 'CREATE TABLE '|| quote_ident(_tbl.newTableName) ||' AS
SELECT region_id, key AS sequential_id, value
FROM (SELECT row_to_json(t.*) AS line, region_id
FROM '|| _tbl.fullNamePath ||' AS t) AS r
JOIN LATERAL json_each_text(r.line) ON (key <> "region_id");';
END LOOP;
END;
$BODY$ LANGUAGE plpgsql;