add MERGE query support. (#700)

src/dialect/mssql/mssql-query-compiler.ts

@@ -1,6 +1,7 @@
 import { AddColumnNode } from '../../operation-node/add-column-node.js'
 import { AlterTableColumnAlterationNode } from '../../operation-node/alter-table-node.js'
 import { DropColumnNode } from '../../operation-node/drop-column-node.js'
+import { MergeQueryNode } from '../../operation-node/merge-query-node.js'
 import { DefaultQueryCompiler } from '../../query-compiler/default-query-compiler.js'
 
 export class MssqlQueryCompiler extends DefaultQueryCompiler {
@@ -73,6 +74,11 @@ export class MssqlQueryCompiler extends DefaultQueryCompiler {
     this.visitNode(node.column)
   }
 
+  protected override visitMergeQuery(node: MergeQueryNode): void {
+    super.visitMergeQuery(node)
+    this.append(';')
+  }
+
   protected override announcesNewColumnDataType(): boolean {
     return false
   }

src/dialect/postgres/postgres-dialect-config.ts

@@ -66,7 +66,7 @@ export type PostgresCursorConstructor = new <T>(
 ) => PostgresCursor<T>
 
 export interface PostgresQueryResult<R> {
-  command: 'UPDATE' | 'DELETE' | 'INSERT' | 'SELECT'
+  command: 'UPDATE' | 'DELETE' | 'INSERT' | 'SELECT' | 'MERGE'
   rowCount: number
   rows: R[]
 }

src/dialect/postgres/postgres-driver.ts

@@ -109,7 +109,8 @@ class PostgresConnection implements DatabaseConnection {
       if (
         result.command === 'INSERT' ||
         result.command === 'UPDATE' ||
-        result.command === 'DELETE'
+        result.command === 'DELETE' ||
+        result.command === 'MERGE'
       ) {
         const numAffectedRows = BigInt(result.rowCount)
 

src/driver/database-connection.ts

@@ -21,7 +21,7 @@ export interface QueryResult<O> {
   readonly numUpdatedOrDeletedRows?: bigint
 
   /**
-   * This is defined for insert, update and delete queries and contains
+   * This is defined for insert, update, delete and merge queries and contains
    * the number of rows the query inserted/updated/deleted.
    */
   readonly numAffectedRows?: bigint