diff --git a/migrations/20210822052026_isnumeric_function.down.sql b/migrations/20210822052026_isnumeric_function.down.sql
new file mode 100644
index 0000000..ea1e4a0
--- /dev/null
+++ b/migrations/20210822052026_isnumeric_function.down.sql
@@ -0,0 +1 @@
+DROP FUNCTION IF EXISTS isnumeric;
diff --git a/migrations/20210822052026_isnumeric_function.up.sql b/migrations/20210822052026_isnumeric_function.up.sql
new file mode 100644
index 0000000..cb0e2a6
--- /dev/null
+++ b/migrations/20210822052026_isnumeric_function.up.sql
@@ -0,0 +1,11 @@
+CREATE OR REPLACE FUNCTION isnumeric(text) RETURNS BOOLEAN AS $$
+DECLARE x NUMERIC;
+BEGIN
+    x = $1::NUMERIC;
+    RETURN TRUE;
+EXCEPTION WHEN others THEN
+    RETURN FALSE;
+END;
+$$
+STRICT
+LANGUAGE plpgsql IMMUTABLE;