fix(API): reduce code duplication between DB entities (#4351)

packages/cli/src/databases/entities/AbstractEntity.ts

@@ -0,0 +1,39 @@
+import { BeforeUpdate, CreateDateColumn, UpdateDateColumn } from 'typeorm';
+import { IsDate, IsOptional } from 'class-validator';
+import config from '../../../config';
+
+const dbType = config.getEnv('database.type');
+
+const timestampSyntax = {
+	sqlite: `STRFTIME('%Y-%m-%d %H:%M:%f', 'NOW')`,
+	postgresdb: 'CURRENT_TIMESTAMP(3)',
+	mysqldb: 'CURRENT_TIMESTAMP(3)',
+	mariadb: 'CURRENT_TIMESTAMP(3)',
+}[dbType];
+
+export const jsonColumnType = dbType === 'sqlite' ? 'simple-json' : 'json';
+export const datetimeColumnType = dbType === 'postgresdb' ? 'timestamptz' : 'datetime';
+
+export abstract class AbstractEntity {
+	@CreateDateColumn({
+		precision: 3,
+		default: () => timestampSyntax,
+	})
+	@IsOptional() // ignored by validation because set at DB level
+	@IsDate()
+	createdAt: Date;
+
+	@UpdateDateColumn({
+		precision: 3,
+		default: () => timestampSyntax,
+		onUpdate: timestampSyntax,
+	})
+	@IsOptional() // ignored by validation because set at DB level
+	@IsDate()
+	updatedAt: Date;
+
+	@BeforeUpdate()
+	setUpdateDate(): void {
+		this.updatedAt = new Date();
+	}
+}