Core

An SQLite database.

A database supports SQL statement execution, transactions and savepoints, custom collation sequences, and custom SQL functions.

let db = try Database()
try db.execute(sql: "create table t1(a);")
try db.execute(sql: "insert into t1 default values;")
let rowCount: Int = db.prepare(sql: "select count(*) from t1;").front()
print("t1 has \(rowCount) rows")

A compiled SQL statement with support for SQL parameter binding and result row processing.

Creation

A statement is not created directly but is obtained from a Database.

let statement = try db.prepare(sql: "select count(*) from t1;")

Parameter Binding

A statement supports binding values to SQL parameters by index or by name.

let statement = try db.prepare(sql: "insert into t1(a, b, c, d, e, f) values (?, ?, ?, :d, :e, :f);")
try statement.bind(value: 30, toParameter: 3)
try statement.bind(value: 40, toParameter: ":d")
try statement.bind(parameterValues: 10, 20)
try statement.bind(parameters: [":f": 60, ":e": 50])

Result Rows

When executed a statement provides zero or more result rows.

try statement.results { row in
    // Do something with `row`
}

for row in statement {
    // Do something with `row`
}

It is generally preferred to use the block-based method because any errors may be explicitly handled instead of silently discarded.

A result row containing one or more columns with type-safe value access.

Creation

A row is not created directly but is obtained from a Statement.

try statement.execute() { row in
    // Do something with `row`
}

Column Value Access

The database-native column value is expressed by DatabaseValue, however custom type conversion is possible when a type implements either the ColumnConvertible or DatabaseSerializable protocol.

The value of columns is accessed by the value(at:) or value(named:) methods.

let value = try row.value(at: 0)
let uuid: UUID = try row.value(named: "session_uuid")

It is also possible to iterate over column values:

for row in statement {
    for value in row {
        // Do something with `value`
    }

}

This allows for simple result row processing at the expense of error handling.