fix: REGEX_EXTRACT - formula function correction

packages/nc-gui/utils/formulaUtils.ts

@@ -482,7 +482,7 @@ const formulas: Record<string, any> = {
         rqd: 0,
       },
     },
-    description: 'Returns an empty string.',
+    description: 'Returns a blank value.',
     syntax: 'BLANK()',
     examples: ['BLANK()'],
   },

packages/nocodb/src/db/functionMappings/pg.ts

@@ -201,7 +201,9 @@ const pg = {
     const pattern = (await fn(pt.arguments[1])).builder;
     return {
       builder: knex.raw(
-        `REGEXP_MATCHES(${source}::text, ${pattern}::text) ${colAlias}`,
+        // use `SUBSTRING` since REGEXP_MATCH returns array value
+        // `REGEXP_MATCH(${source}::text, ${pattern}::text) ${colAlias}`,
+        `SUBSTRING(${source}::text from ${pattern}::text) ${colAlias}`,
       ),
     };
   },