Extracting column check constraints

src/deprecatia/integration-tests/__snapshots__/index.test.js.snap

@@ -4,6 +4,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
 {
   "tables": [
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -277,6 +278,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -821,6 +823,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -1025,6 +1028,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -1313,6 +1317,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -1517,6 +1522,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -2199,6 +2205,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -3073,6 +3080,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -3316,6 +3324,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -3555,6 +3564,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -3848,6 +3858,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -4052,6 +4063,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -4508,6 +4520,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -5032,6 +5045,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,
@@ -5763,6 +5777,7 @@ exports[`extractSchema > dvd-rental database > Should match snapshot 1`] = `
       "tags": {},
     },
     {
+      "checks": [],
       "columns": [
         {
           "comment": undefined,

src/kinds/extractTable.test.ts

@@ -4,6 +4,7 @@ import { describe, expect } from "vitest";
 import { test, testWith } from "../tests/useSchema";
 import extractTable, {
   ColumnReference,
+  TableCheck,
   TableColumn,
   TableDetails,
 } from "./extractTable";
@@ -44,6 +45,7 @@ describe("extractTable", () => {
         is_typed: "NO",
         commit_action: null,
       },
+      checks: [],
       columns: [
         {
           name: "id",
@@ -160,6 +162,28 @@ describe("extractTable", () => {
     expect(actual).toEqual(expected);
   });
 
+  test("it should fetch table checks", async ({ knex: [db] }) => {
+    await db.raw(`create table test.some_table_with_checks (
+        id integer constraint id_check check (id > 0),
+        products TEXT[],
+        number_of_products INT,
+        constraint products_len_check check (array_length(products, 1) = number_of_products)
+    )`);
+
+    const result = await extractTable(db, makePgType("some_table_with_checks"));
+    const actual = result.checks;
+
+    const expected: TableCheck[] = [
+      { name: "id_check", clause: "id > 0" },
+      {
+        name: "products_len_check",
+        clause: "array_length(products, 1) = number_of_products",
+      },
+    ];
+
+    expect(actual).toEqual(expected);
+  });
+
   test("it should handle domains, composite types, ranges and enums as well as arrays of those", async ({
     knex: [db],
   }) => {

src/kinds/extractTable.ts

@@ -36,6 +36,11 @@ export type TableColumnType = {
   kind: "base" | "range" | "domain" | "composite" | "enum";
 };
 
+export interface TableCheck {
+  name: string;
+  clause: string;
+}
+
 export interface TableColumn {
   name: string;
   expandedType: string;
@@ -61,6 +66,7 @@ export interface TableColumn {
 
 export interface TableDetails extends PgType<"table"> {
   columns: TableColumn[];
+  checks: TableCheck[];
   informationSchemaValue: InformationSchemaTable;
 }
 
@@ -215,7 +221,45 @@ const extractTable = async (
     reference: row.references[0] ?? null,
   }));
 
-  return { ...table, informationSchemaValue, columns };
+  const checkQuery = await db.raw(
+    `
+    SELECT
+      source_namespace.nspname as "schema",
+      source_class.relname as "table",
+      json_agg(json_build_object(
+                 'name', con.conname,
+                 'clause', SUBSTRING(pg_get_constraintdef(con.oid) FROM 7)
+      )) as checks
+    FROM
+     pg_constraint con,
+     pg_class source_class,
+     pg_namespace source_namespace 
+    WHERE
+     source_class.relname = :table_name
+     AND source_namespace.nspname = :schema_name
+     AND conrelid = source_class.oid 
+     AND source_class.relnamespace = source_namespace.oid 
+     AND con.contype = 'c'
+    GROUP BY source_namespace.nspname, source_class.relname;
+  `,
+    { table_name: table.name, schema_name: table.schemaName },
+  );
+
+  const checks = checkQuery.rows
+    .flatMap((row: any) => row.checks as TableCheck)
+    .map(({ name, clause }: TableCheck) => {
+      const numberOfBrackets =
+        clause.startsWith("((") && clause.endsWith("))") ? 2 : 1;
+      return {
+        name,
+        clause: clause.slice(
+          numberOfBrackets,
+          clause.length - numberOfBrackets,
+        ),
+      };
+    });
+
+  return { ...table, checks, informationSchemaValue, columns };
 };
 
 export default extractTable;