feat: add table comment for postgres (#10613)

src/driver/postgres/PostgresQueryRunner.ts

@@ -601,6 +601,11 @@ export class PostgresQueryRunner
                 downQueries.push(this.dropIndexSql(table, index))
             })
         }
+        
+        if (table.comment) {
+            upQueries.push(new Query("COMMENT ON TABLE " + this.escapePath(table) + " IS '" + table.comment + "'"));
+            downQueries.push(new Query("COMMENT ON TABLE " + this.escapePath(table) + " IS NULL"));
+        }
 
         await this.executeQueries(upQueries, downQueries)
     }
@@ -3276,10 +3281,14 @@ export class PostgresQueryRunner
         const currentSchema = await this.getCurrentSchema()
         const currentDatabase = await this.getCurrentDatabase()
 
-        const dbTables: { table_schema: string; table_name: string }[] = []
+        const dbTables: {
+            table_schema: string
+            table_name: string
+            table_comment: string
+        }[] = []
 
         if (!tableNames) {
-            const tablesSql = `SELECT "table_schema", "table_name" FROM "information_schema"."tables"`
+            const tablesSql = `SELECT "table_schema", "table_name", obj_description(('"' || "table_schema" || '"."' || "table_name" || '"')::regclass, 'pg_class') AS table_comment FROM "information_schema"."tables"`
             dbTables.push(...(await this.query(tablesSql)))
         } else {
             const tablesCondition = tableNames
@@ -3292,7 +3301,7 @@ export class PostgresQueryRunner
                 .join(" OR ")
 
             const tablesSql =
-                `SELECT "table_schema", "table_name" FROM "information_schema"."tables" WHERE ` +
+                `SELECT "table_schema", "table_name", obj_description(('"' || "table_schema" || '"."' || "table_name" || '"')::regclass, 'pg_class') AS table_comment FROM "information_schema"."tables" WHERE ` +
                 tablesCondition
             dbTables.push(...(await this.query(tablesSql)))
         }
@@ -3416,6 +3425,7 @@ export class PostgresQueryRunner
                 const schema = getSchemaFromKey(dbTable, "table_schema")
                 table.database = currentDatabase
                 table.schema = dbTable["table_schema"]
+                table.comment = dbTable["table_comment"]
                 table.name = this.driver.buildTableName(
                     dbTable["table_name"],
                     schema,
@@ -4318,7 +4328,7 @@ export class PostgresQueryRunner
         table: Table | View,
         indexOrName: TableIndex | string,
     ): Query {
-        let indexName = InstanceChecker.isTableIndex(indexOrName)
+        const indexName = InstanceChecker.isTableIndex(indexOrName)
             ? indexOrName.name
             : indexOrName
         const concurrent = InstanceChecker.isTableIndex(indexOrName)
@@ -4721,12 +4731,43 @@ export class PostgresQueryRunner
     /**
      * Change table comment.
      */
-    changeTableComment(
+    async changeTableComment(
         tableOrName: Table | string,
-        comment?: string,
+        newComment?: string,
     ): Promise<void> {
-        throw new TypeORMError(
-            `postgres driver does not support change table comment.`,
+        const upQueries: Query[] = []
+        const downQueries: Query[] = []
+
+        const table = InstanceChecker.isTable(tableOrName)
+            ? tableOrName
+            : await this.getCachedTable(tableOrName)
+
+        newComment = this.escapeComment(newComment)
+        const comment = this.escapeComment(table.comment)
+        
+        if (newComment === comment) {
+            return
+        }
+
+        const newTable = table.clone()
+
+        upQueries.push(
+            new Query(
+                `COMMENT ON TABLE ${this.escapePath(
+                    newTable,
+                )} IS ${newComment}`,
+            ),
         )
+
+        downQueries.push(
+            new Query(
+                `COMMENT ON TABLE ${this.escapePath(table)} IS ${comment}`,
+            ),
+        )
+
+        await this.executeQueries(upQueries, downQueries)
+
+        table.comment = newTable.comment
+        this.replaceCachedTable(table, newTable)
     }
 }

src/schema-builder/RdbmsSchemaBuilder.ts

@@ -602,7 +602,10 @@ export class RdbmsSchemaBuilder implements SchemaBuilder {
             )
             if (!table) continue
 
-            if (DriverUtils.isMySQLFamily(this.connection.driver)) {
+            if (
+                DriverUtils.isMySQLFamily(this.connection.driver) ||
+                this.connection.driver.options.type === 'postgres'
+            ) {
                 const newComment = metadata.comment
                 await this.queryRunner.changeTableComment(table, newComment)
             }

test/github-issues/10612/entity/ExampleEntity.ts

@@ -0,0 +1,8 @@
+import { Entity } from "../../../../src/decorator/entity/Entity"
+import { PrimaryGeneratedColumn } from "../../../../src/decorator/columns/PrimaryGeneratedColumn"
+
+@Entity({ name: "example", comment: "table comment" })
+export class ExampleEntity {
+    @PrimaryGeneratedColumn()
+    id: number
+}

test/github-issues/10612/issue-10612.ts

@@ -0,0 +1,86 @@
+import { DataSource } from "../../../src"
+import {
+    closeTestingConnections,
+    createTestingConnections,
+    reloadTestingDatabases,
+} from "../../utils/test-utils"
+import { ExampleEntity } from "./entity/ExampleEntity"
+import { expect } from "chai"
+
+describe("github issues > #10612", () => {
+    let dataSources: DataSource[]
+
+    before(async () => {
+        dataSources = await createTestingConnections({
+            entities: [ExampleEntity],
+            enabledDrivers: ["postgres"],
+        })
+    })
+
+    beforeEach(() => reloadTestingDatabases(dataSources))
+    after(() => closeTestingConnections(dataSources))
+
+    it("add table comment", async () => {
+        await Promise.all(
+            dataSources.map(async (dataSource) => {
+                const sql =
+                    "SELECT obj_description('example'::regclass::oid, 'pg_class') AS table_comment"
+
+                const result = await dataSource.manager.query(sql)
+                expect(result).to.be.eql([{ table_comment: "table comment" }])
+            }),
+        )
+    })
+
+    it("should correctly change table comment and change", async () => {
+        await Promise.all(
+            dataSources.map(async (dataSource) => {
+                const queryRunner = dataSource.createQueryRunner()
+                const table = await queryRunner.getTable("example")
+
+                await queryRunner.changeTableComment(
+                    table!,
+                    "new table comment",
+                )
+                const sql =
+                    "SELECT obj_description('example'::regclass::oid, 'pg_class') AS table_comment"
+
+                let result = await dataSource.manager.query(sql)
+                expect(result).to.be.eql([
+                    { table_comment: "new table comment" },
+                ])
+
+                // revert changes
+                await queryRunner.executeMemoryDownSql()
+
+                result = await dataSource.manager.query(sql)
+                expect(result).to.be.eql([{ table_comment: "table comment" }])
+
+                await queryRunner.release()
+            }),
+        )
+    })
+
+    it("should correctly synchronize when table comment change", async () => {
+        await Promise.all(
+            dataSources.map(async (dataSource) => {
+                const queryRunner = dataSource.createQueryRunner()
+
+                const exampleMetadata = dataSource.getMetadata(ExampleEntity)
+                exampleMetadata.comment = "change table comment"
+
+                await dataSource.synchronize()
+
+                const sql =
+                    "SELECT obj_description('example'::regclass::oid, 'pg_class') AS table_comment"
+
+                const result = await dataSource.manager.query(sql)
+                expect(result).to.be.eql([
+                    { table_comment: "change table comment" },
+                ])
+
+                await queryRunner.release()
+            }),
+        )
+    })
+})