Using raw SQL query fragments

raw() helper

When you want to use a raw SQL fragment as part of your query, you can use the raw() helper. It creates a raw SQL query fragment instance that can be assigned to a property or part of a filter. This fragment is represented by RawQueryFragment class instance that can be serialized to a string, so it can be used both as an object value and key. When serialized, the fragment key gets cached and only such cached key will be recognized by the ORM. This adds a runtime safety to the raw query fragments.

raw() helper is required since v6 to use a raw SQL fragment in your query, both through EntityManager and QueryBuilder.

// as a value
await em.find(User, { time: raw('now()') });

// as a key
await em.find(User, { [raw('lower(name)')]: name.toLowerCase() });

// value can be empty array
await em.find(User, { [raw('(select 1 = 1)')]: [] });

The raw helper supports several signatures, you can pass in a callback that receives the current property alias:

await em.find(User, { [raw(alias => `lower(${alias}.name)`)]: name.toLowerCase() });

Raw fragments in filters

When using raw query fragment inside a filter, you might have to use a callback signature to create new raw instance for every filter usage - namely when you use the fragment as an object key, which requires its serialization.

@Filter({ name: 'long', cond: () => ({ [raw('length(perex)')]: { $gt: 10000 } }) })

sql tagged templates

You can also use the sql tagged template function, which works the same, but supports only the simple string signature:

// as a value
await em.find(User, { time: sql`now()` });

// as a key
await em.find(User, { [sql`lower(name)`]: name.toLowerCase() });

// value can be empty array
await em.find(User, { [sql`(select ${1} = ${1})`]: [] });

sql.ref()

When you want to refer to a column, you can use the sql.ref() function:

await em.find(User, { foo: sql`bar` });

sql.now()

When you want to define a default value for a datetime column, you can use the sql.now() function. It resolves to current_timestamp SQL function, and accepts a length parameter.

@Property({ default: sql.now() })
createdAt: Date & Opt;

sql.lower() and sql.upper()

To convert a key to lowercase or uppercase, you can use the sql.lower() and sql.upper() functions

const books = await orm.em.find(Book, {
  [sql.upper('title')]: 'TITLE',
});

Aliasing

To select a raw fragment, we need to alias it. For that, we can use sql`(select 1 + 1)`.as('<alias>').