SqlJs Statement

Represents a prepared statement. Prepared statements allow you to have a template sql string, that you can execute multiple times with different parameters.

You can't instantiate this class directly, you have to use a Database object in order to create a statement.

Warning: When you close a database (using db.close()), all its statements are closed too and become unusable.

Statements can't be created by the API user directly, only by Database::prepare

Constructor

new Statement(stmt1, db)

Parameters:
NameTypeDescription
stmt1number

The SQLite statement reference

dbDatabase

The database from which this statement was created

Source
See

Methods

["bind"](values) → {boolean}

Bind values to the parameters, after having reset the statement. If values is null, do nothing and return true.

SQL statements can have parameters, named '?', '?NNN', ':VVV', '@VVV', '$VVV', where NNN is a number and VVV a string. This function binds these parameters to the given values.

Warning: ':', '@', and '$' are included in the parameters names

Value types

Javascript typeSQLite type
numberREAL, INTEGER
booleanINTEGER
stringTEXT
Array, Uint8ArrayBLOB
nullNULL
Parameters:
NameTypeDescription
valuesStatement.BindParams

The values to bind

Source
See
Throws:

SQLite Error

Type
String
Returns:

true if it worked

Type: 
boolean
Examples

Bind values to named parameters

    var stmt = db.prepare(
        "UPDATE test SET a=@newval WHERE id BETWEEN $mini AND $maxi"
    );
    stmt.bind({$mini:10, $maxi:20, '@newval':5});

Bind values to anonymous parameters

// Create a statement that contains parameters like '?', '?NNN'
var stmt = db.prepare("UPDATE test SET a=? WHERE id BETWEEN ? AND ?");
// Call Statement.bind with an array as parameter
stmt.bind([5, 10, 20]);

["free"]() → {boolean}

Free the memory used by the statement

Source
Returns:

true in case of success

Type: 
boolean

["freemem"]()

Free the memory allocated during parameter binding

Source

["get"](paramsopt) → {Array.<Database.SqlValue>}

Get one row of results of a statement. If the first parameter is not provided, step must have been called before.

Parameters:
NameTypeAttributesDescription
paramsStatement.BindParams<optional>

If set, the values will be bound to the statement before it is executed

Source
Returns:

One row of result

Type: 
Array.<Database.SqlValue>
Example

Print all the rows of the table test to the console

    var stmt = db.prepare("SELECT * FROM test");
    while (stmt.step()) console.log(stmt.get());

["getAsObject"](paramsopt) → {Object.<string, Database.SqlValue>}

Get one row of result as a javascript object, associating column names with their value in the current row.

Parameters:
NameTypeAttributesDescription
paramsStatement.BindParams<optional>

If set, the values will be bound to the statement, and it will be executed

Source
See
  • Statement.get
Returns:

The row of result

Type: 
Object.<string, Database.SqlValue>
Example
var stmt = db.prepare(
            "SELECT 5 AS nbr, x'010203' AS data, NULL AS null_value;"
        );
        stmt.step(); // Execute the statement
        console.log(stmt.getAsObject());
        // Will print {nbr:5, data: Uint8Array([1,2,3]), null_value:null}

["getColumnNames"]() → {Array.<string>}

Get the list of column names of a row of result of a statement.

Source
Returns:

The names of the columns

Type: 
Array.<string>
Example
var stmt = db.prepare(
        "SELECT 5 AS nbr, x'616200' AS data, NULL AS null_value;"
    );
    stmt.step(); // Execute the statement
    console.log(stmt.getColumnNames());
    // Will print ['nbr','data','null_value']

["getNormalizedSQL"]() → {string}

Get the SQLite's normalized version of the SQL string used in preparing this statement. The meaning of "normalized" is not well-defined: see the SQLite documentation.

Source
Returns:

The normalized SQL string

Type: 
string
Example
db.run("create table test (x integer);");
     stmt = db.prepare("select * from test where x = 42");
     // returns "SELECT*FROM test WHERE x=?;"

["getSQL"]() → {string}

Get the SQL string used in preparing this statement.

Source
Returns:

The SQL string

Type: 
string

["reset"]()

Reset a statement, so that it's parameters can be bound to new values It also clears all previous bindings, freeing the memory used by bound parameters.

Source

["run"](valuesopt)

Shorthand for bind + step + reset Bind the values, execute the statement, ignoring the rows it returns, and resets it

Parameters:
NameTypeAttributesDescription
valuesStatement.BindParams<optional>

Value to bind to the statement

Source

["step"]() → {boolean}

Execute the statement, fetching the next line of result, that can be retrieved with Statement.get.

Source
Throws:

SQLite Error

Type
String
Returns:

true if a row of result available

Type: 
boolean

Type Definitions

BindParams

Type:
Source