$app
is the main interface to interact with your database.
$app.db()
returns a dbx.Builder
that could run all kind of SQL statements, including raw queries.
For more details and examples how to interact with Record and Collection models programmatically you could also check Collection operations and Record operations sections.
Executing queries
To execute DB queries you can start with the newQuery("...")
statement and then call one of:
execute()
- for any query statement that is not meant to retrieve data:$app.db() .newQuery("CREATE INDEX name_idx ON users (name)") .execute() // throw an error on db failure
one()
- to populate a single row intoDynamicModel
object:const result = new DynamicModel({ // describe the shape of the data (used also as initial values) "id": "", "status": false, "age": 0, // use -0 for a float value "roles": [], // serialized json db arrays are decoded as plain arrays }) $app.db() .newQuery("SELECT id, status, age, roles FROM users WHERE id=1") .one(result) // throw an error on db failure or missing row console.log(result.id)
all()
- to populate multiple rows into an array of objects (note that the array must be created witharrayOf
):const result = arrayOf(new DynamicModel({ // describe the shape of the data (used also as initial values) "id": "", "status": false, "age": 0, // use -0 for a float value "roles": [], // serialized json db arrays are decoded as plain arrays })) $app.db() .newQuery("SELECT id, status, age, roles FROM users LIMIT 100") .all(result) // throw an error on db failure if (result.length > 0) { console.log(result[0].id) }
Binding parameters
To prevent SQL injection attacks, you should use named parameters for any expression value that comes from
user input. This could be done using the named {:paramName}
placeholders in your SQL statement and then define the parameter values for the query with
bind(params)
. For example:
const result = arrayOf(new DynamicModel({
"name": "",
"created": "",
}))
$app.db()
.newQuery("SELECT name, created FROM posts WHERE created >= {:from} and created <= {:to}")
.bind({
"from": "2023-06-25 00:00:00.000Z",
"to": "2023-06-28 23:59:59.999Z",
})
.all(result)
console.log(result.length)
Query builder
Instead of writting plain SQLs, you can also compose SQL statements programmatically using the db query
builder.
Every SQL keyword has a corresponding query building method. For example, SELECT
corresponds
to select()
, FROM
corresponds to from()
,
WHERE
corresponds to where()
, and so on.
const result = arrayOf(new DynamicModel({
"id": "",
"email": "",
}))
$app.db()
.select("id", "email")
.from("users")
.andWhere($dbx.like("email", "example.com"))
.limit(100)
.orderBy("created ASC")
.all(result)
select(), andSelect(), distinct()
The select(...cols)
method initializes a SELECT
query builder. It accepts a list
of the column names to be selected.
To add additional columns to an existing select query, you can call andSelect()
.
To select distinct rows, you can call distinct()
.
$app.db()
.select("id", "avatar as image")
.andSelect("(firstName || ' ' || lastName) as fullName")
.distinct()
...
from()
The from(...tables)
method specifies which tables to select from (plain table names are automatically
quoted).
$app.db()
.select("table1.id", "table2.name")
.from("table1", "table2")
...
join()
The join(type, table, on)
method specifies a JOIN
clause. It takes 3 parameters:
type
- join type string likeINNER JOIN
,LEFT JOIN
, etc.table
- the name of the table to be joinedon
- optionaldbx.Expression
as anON
clause
For convenience, you can also use the shortcuts innerJoin(table, on)
,
leftJoin(table, on)
,
rightJoin(table, on)
to specify INNER JOIN
, LEFT JOIN
and
RIGHT JOIN
, respectively.
$app.db()
.select("users.*")
.from("users")
.innerJoin("profiles", $dbx.exp("profiles.user_id = users.id"))
.join("FULL OUTER JOIN", "department", $dbx.exp("department.id = {:id}", {id: "someId"}))
...
where(), andWhere(), orWhere()
The where(exp)
method specifies the WHERE
condition of the query.
You can also use andWhere(exp)
or orWhere(exp)
to append additional one or more
conditions to an existing WHERE
clause.
Each where condition accepts a single dbx.Expression
(see below for full list).
/*
SELECT users.*
FROM users
WHERE id = "someId" AND
status = "public" AND
name like "%john%" OR
(
role = "manager" AND
fullTime IS TRUE AND
experience > 10
)
*/
$app.db()
.select("users.*")
.from("users")
.where($dbx.exp("id = {:id}", { id: "someId" }))
.andWhere($dbx.hashExp({ status: "public" }))
.andWhere($dbx.like("name", "john"))
.orWhere($dbx.and(
$dbx.hashExp({
role: "manager",
fullTime: true,
}),
$dbx.exp("experience > {:exp}", { exp: 10 })
))
...
The following dbx.Expression
methods are available:
$dbx.exp(raw, optParams)
Generates an expression with the specified raw query fragment. Use theoptParams
to bind parameters to the expression.$dbx.exp("status = 'public'") $dbx.exp("total > {:min} AND total < {:max}", { min: 10, max: 30 })
$dbx.hashExp(pairs)
Generates a hash expression from a map whose keys are DB column names which need to be filtered according to the corresponding values.// slug = "example" AND active IS TRUE AND tags in ("tag1", "tag2", "tag3") AND parent IS NULL $dbx.hashExp({ slug: "example", active: true, tags: ["tag1", "tag2", "tag3"], parent: null, })
$dbx.not(exp)
Negates a single expression by wrapping it withNOT()
.// NOT(status = 1) $dbx.not($dbx.exp("status = 1"))
$dbx.and(...exps)
Creates a new expression by concatenating the specified ones withAND
.// (status = 1 AND username like "%john%") $dbx.and($dbx.exp("status = 1"), $dbx.like("username", "john"))
$dbx.or(...exps)
Creates a new expression by concatenating the specified ones withOR
.// (status = 1 OR username like "%john%") $dbx.or($dbx.exp("status = 1"), $dbx.like("username", "john"))
$dbx.in(col, ...values)
Generates anIN
expression for the specified column and the list of allowed values.// status IN ("public", "reviewed") $dbx.in("status", "public", "reviewed")
$dbx.notIn(col, ...values)
Generates anNOT IN
expression for the specified column and the list of allowed values.// status NOT IN ("public", "reviewed") $dbx.notIn("status", "public", "reviewed")
$dbx.like(col, ...values)
Generates aLIKE
expression for the specified column and the possible strings that the column should be like. If multiple values are present, the column should be like all of them.
By default, each value will be surrounded by "%" to enable partial matching. Special characters like "%", "\", "_" will also be properly escaped. You may callescape(...pairs)
and/ormatch(left, right)
to change the default behavior.// name LIKE "%test1%" AND name LIKE "%test2%" $dbx.like("name", "test1", "test2") // name LIKE "test1%" $dbx.like("name", "test1").match(false, true)
$dbx.notLike(col, ...values)
Generates aNOT LIKE
expression in similar manner aslike()
.// name NOT LIKE "%test1%" AND name NOT LIKE "%test2%" $dbx.notLike("name", "test1", "test2") // name NOT LIKE "test1%" $dbx.notLike("name", "test1").match(false, true)
$dbx.orLike(col, ...values)
This is similar tolike()
except that the column must be one of the provided values, aka. multiple values are concatenated withOR
instead ofAND
.// name LIKE "%test1%" OR name LIKE "%test2%" $dbx.orLike("name", "test1", "test2") // name LIKE "test1%" OR name LIKE "test2%" $dbx.orLike("name", "test1", "test2").match(false, true)
$dbx.orNotLike(col, ...values)
This is similar tonotLike()
except that the column must not be one of the provided values, aka. multiple values are concatenated withOR
instead ofAND
.// name NOT LIKE "%test1%" OR name NOT LIKE "%test2%" $dbx.orNotLike("name", "test1", "test2") // name NOT LIKE "test1%" OR name NOT LIKE "test2%" $dbx.orNotLike("name", "test1", "test2").match(false, true)
$dbx.exists(exp)
Prefix withEXISTS
the specified expression (usually a subquery).// EXISTS (SELECT 1 FROM users WHERE status = 'active') $dbx.exists(dbx.exp("SELECT 1 FROM users WHERE status = 'active'"))
$dbx.notExists(exp)
Prefix withNOT EXISTS
the specified expression (usually a subquery).// NOT EXISTS (SELECT 1 FROM users WHERE status = 'active') $dbx.notExists(dbx.exp("SELECT 1 FROM users WHERE status = 'active'"))
$dbx.between(col, from, to)
Generates aBETWEEN
expression with the specified range.// age BETWEEN 3 and 99 $dbx.between("age", 3, 99)
$dbx.notBetween(col, from, to)
Generates aNOT BETWEEN
expression with the specified range.// age NOT BETWEEN 3 and 99 $dbx.notBetween("age", 3, 99)
orderBy(), andOrderBy()
The orderBy(...cols)
specifies the ORDER BY
clause of the query.
A column name can contain "ASC" or "DESC" to indicate its ordering direction.
You can also use andOrderBy(...cols)
to append additional columns to an existing
ORDER BY
clause.
$app.db()
.select("users.*")
.from("users")
.orderBy("created ASC", "updated DESC")
.andOrderBy("title ASC")
...
groupBy(), andGroupBy()
The groupBy(...cols)
specifies the GROUP BY
clause of the query.
You can also use andGroupBy(...cols)
to append additional columns to an existing
GROUP BY
clause.
$app.db()
.select("users.*")
.from("users")
.groupBy("department", "level")
...
having(), andHaving(), orHaving()
The having(exp)
specifies the HAVING
clause of the query.
Similarly to
where(exp)
, it accept a single dbx.Expression
(see all available expressions
listed above).
You can also use andHaving(exp)
or orHaving(exp)
to append additional one or
more conditions to an existing HAVING
clause.
$app.db()
.select("users.*")
.from("users")
.groupBy("department", "level")
.having($dbx.exp("sum(level) > {:sum}", { sum: 10 }))
...
limit()
The limit(number)
method specifies the LIMIT
clause of the query.
$app.db()
.select("users.*")
.from("users")
.limit(30)
...
offset()
The offset(number)
method specifies the OFFSET
clause of the query. Usually used
together with limit(number)
.
$app.db()
.select("users.*")
.from("users")
.offset(5)
.limit(30)
...
Transaction
To execute multiple queries in a transaction you can use
$app.runInTransaction(fn)
.
The DB operations are persisted only if the transaction completes without throwing an error.
It is safe to nest runInTransaction
calls as long as you use the callback's
txApp
argument.
Inside the transaction function always use its txApp
argument and not the original
$app
instance because we allow only a single writer/transaction at a time and it could
result in a deadlock.
To avoid performance issues, try to minimize slow/long running tasks such as sending emails, connecting to external services, etc. as part of the transaction.
$app.runInTransaction((txApp) => {
// update a record
const record = txApp.findRecordById("articles", "RECORD_ID")
record.set("status", "active")
txApp.save(record)
// run a custom raw query (doesn't fire event hooks)
txApp.db().newQuery("DELETE FROM articles WHERE status = 'pending'").execute()
})