sql writer

pkg/writers/pgsql/templates/base_constraint.tmpl

@@ -0,0 +1,39 @@
+{{/* Base constraint template */}}
+{{- define "constraint_base" -}}
+ALTER TABLE {{.SchemaName}}.{{.TableName}}
+  ADD CONSTRAINT {{.ConstraintName}}
+  {{block "constraint_definition" .}}{{end}};
+{{- end -}}
+
+{{/* Drop constraint with check */}}
+{{- define "drop_constraint_safe" -}}
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1 FROM information_schema.table_constraints
+        WHERE table_schema = '{{.SchemaName}}'
+          AND table_name = '{{.TableName}}'
+          AND constraint_name = '{{.ConstraintName}}'
+    ) THEN
+        ALTER TABLE {{.SchemaName}}.{{.TableName}}
+          DROP CONSTRAINT {{.ConstraintName}};
+    END IF;
+END;
+$$;
+{{- end -}}
+
+{{/* Add constraint with existence check */}}
+{{- define "add_constraint_safe" -}}
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1 FROM information_schema.table_constraints
+        WHERE table_schema = '{{.SchemaName}}'
+          AND table_name = '{{.TableName}}'
+          AND constraint_name = '{{.ConstraintName}}'
+    ) THEN
+        {{template "constraint_base" .}}
+    END IF;
+END;
+$$;
+{{- end -}}