Add support for WHERE LIKE clauses in SQL drivers via native regexps

TODO.md

@@ -5,4 +5,3 @@
 - debugging section in docs (add logger, set debug mode, query logger)
 - test request context is properly garbage collected or we need some clean manual up
 - single table inheritance
-- support for LIKE clauses in SQL drivers

docs/usage-with-sql.md

@@ -111,6 +111,21 @@ EntityManager.transactional(cb: (em: EntityManager) => Promise<any>): Promise<an
 
 Keep in mind transactions are supported only in MySQL driver currently. 
 
+## LIKE queries
+
+SQL do support LIKE queries via native JS regular expressions:
+
+```typescript
+const author1 = new Author2('Author 1', '[email protected]');
+const author2 = new Author2('Author 2', '[email protected]');
+const author3 = new Author2('Author 3', '[email protected]');
+await orm.em.persist([author1, author2, author3]);
+
+// finds authors with email like '%exa%le.c_m'
+const authors = await orm.em.find(Author2, { email: /exa.*le\.c.m$/ }); 
+console.log(authors); // all 3 authors found
+```
+
 ## Native collection methods
 
 Sometimes you need to perform some bulk operation, or you just want to populate your

lib/QueryBuilder.ts

@@ -196,6 +196,8 @@ export class QueryBuilder {
     Object.values(this._cond).forEach(cond => {
       if (Utils.isObject(cond) && cond.$in) {
         return ret.push(...cond.$in);
+      } else if (cond instanceof RegExp) {
+        return ret.push(this.getRegExpParam(cond));
       }
 
       ret.push(cond);
@@ -222,6 +224,8 @@ export class QueryBuilder {
 
     if (value && Utils.isObject(value) && value.$in) {
       ret += ` IN (${Object.keys(value.$in).map(() => '?').join(', ')})`;
+    } else if (value instanceof RegExp) {
+      ret += ' LIKE ?';
     } else if (value) {
       ret += ' = ?';
     }
@@ -330,6 +334,29 @@ export class QueryBuilder {
     return this.metadata[entityName] ? this.metadata[entityName].collection : entityName;
   }
 
+  private getRegExpParam(re: RegExp): string {
+    const value = re.source
+      .replace(/\.\*/g, '%') // .* -> %
+      .replace(/\./g, '_')   // .  -> _
+      .replace(/\\_/g, '.')  // \. -> .
+      .replace(/^\^/g, '')   // remove ^ from start
+      .replace(/\$$/g, '');  // remove $ from end
+
+    if (re.source.startsWith('^') && re.source.endsWith('$')) {
+      return value;
+    }
+
+    if (re.source.startsWith('^')) {
+      return value + '%';
+    }
+
+    if (re.source.endsWith('$')) {
+      return '%' + value;
+    }
+
+    return `%${value}%`;
+  }
+
 }
 
 export enum QueryType {

tests/EntityManager.mysql.test.ts

@@ -274,6 +274,20 @@ describe('EntityManagerMySql', () => {
     expect(ref.isInitialized()).toBe(true);
   });
 
+  test('findOne supports regexps', async () => {
+    const author1 = new Author2('Author 1', '[email protected]');
+    const author2 = new Author2('Author 2', '[email protected]');
+    const author3 = new Author2('Author 3', '[email protected]');
+    await orm.em.persist([author1, author2, author3]);
+    orm.em.clear();
+
+    const authors = await orm.em.find(Author2, { email: /exa.*le\.c.m$/ });
+    expect(authors.length).toBe(3);
+    expect(authors[0].name).toBe('Author 1');
+    expect(authors[1].name).toBe('Author 2');
+    expect(authors[2].name).toBe('Author 3');
+  });
+
   test('stable results of serialization', async () => {
     const god = new Author2('God', '[email protected]');
     const bible = new Book2('Bible', god);

tests/EntityManager.sqlite.test.ts

@@ -257,6 +257,20 @@ describe('EntityManagerSqlite', () => {
     expect(ref.isInitialized()).toBe(true);
   });
 
+  test('findOne supports regexps', async () => {
+    const author1 = new Author2('Author 1', '[email protected]');
+    const author2 = new Author2('Author 2', '[email protected]');
+    const author3 = new Author2('Author 3', '[email protected]');
+    await orm.em.persist([author1, author2, author3]);
+    orm.em.clear();
+
+    const authors = await orm.em.find(Author2, { email: /exa.*le\.c.m$/ });
+    expect(authors.length).toBe(3);
+    expect(authors[0].name).toBe('Author 1');
+    expect(authors[1].name).toBe('Author 2');
+    expect(authors[2].name).toBe('Author 3');
+  });
+
   test('stable results of serialization', async () => {
     const god = new Author2('God', '[email protected]');
     const bible = new Book2('Bible', god);

tests/QueryBuilder.test.ts

@@ -26,6 +26,28 @@ describe('QueryBuilder', () => {
     expect(qb.getParams()).toEqual(['test 123', 'lol 321', PublisherType.GLOBAL, 2, 1]);
   });
 
+  test('select by regexp', async () => {
+    let qb = orm.em.createQueryBuilder(Publisher2.name);
+    qb.select('*').where({ name: /test/ });
+    expect(qb.getQuery()).toEqual('SELECT `e0`.* FROM `publisher2` AS `e0` WHERE `e0`.`name` LIKE ?');
+    expect(qb.getParams()).toEqual(['%test%']);
+
+    qb = orm.em.createQueryBuilder(Publisher2.name);
+    qb.select('*').where({ name: /^test/ });
+    expect(qb.getQuery()).toEqual('SELECT `e0`.* FROM `publisher2` AS `e0` WHERE `e0`.`name` LIKE ?');
+    expect(qb.getParams()).toEqual(['test%']);
+
+    qb = orm.em.createQueryBuilder(Publisher2.name);
+    qb.select('*').where({ name: /t.st$/ });
+    expect(qb.getQuery()).toEqual('SELECT `e0`.* FROM `publisher2` AS `e0` WHERE `e0`.`name` LIKE ?');
+    expect(qb.getParams()).toEqual(['%t_st']);
+
+    qb = orm.em.createQueryBuilder(Publisher2.name);
+    qb.select('*').where({ name: /^c.o.*l-te.*st\.c.m$/ });
+    expect(qb.getQuery()).toEqual('SELECT `e0`.* FROM `publisher2` AS `e0` WHERE `e0`.`name` LIKE ?');
+    expect(qb.getParams()).toEqual(['c_o%l-te%st.c_m']);
+  });
+
   test('select by m:1', async () => {
     const qb = orm.em.createQueryBuilder(Author2.name);
     qb.select('*').where({ favouriteBook: 123 });