QQmlSqlQuery QML Type

The QmlSqlQuery class provides a means of executing and manipulating SQL statements. More...

Import Statement: import QmlSql 1.0

List of all members, including inherited members

Properties

connectionName : string
errorString : string
lastQuery : string
lastQueryOutPut : string
queryString : string

Methods

void exec()
void execWithQuery(string connectionName, string queryString)

Detailed Description

QmlSqlQuery encapsulates the functionality involved in creating, navigating and retrieving data from SQL queries which are executed on a QmlSqlDatabase. It can be used to execute DML (data manipulation language) statements, such as SELECT, INSERT, UPDATE and DELETE, as well as DDL (data definition language) statements, such as CREATE TABLE. It can also be used to execute database-specific commands which are not standard SQL (e.g. SET DATESTYLE=ISO for PostgreSQL).

Example: say that you have a QmlSqlDatabase with the connectionName of "master-connection"


  QmlSqlQuery{
      connectionName: "master-connection"
      queryString: "SELECT * FROM SOMETABLE"
      onDone: {
          console.log(lastQueryOutPut)
      }
  }

Warning: You must load the SQL driver via QmlSqlDatabase and open the connection before a QmlSqlQuery is created. Also, the connection must remain open while the query exists. Otherwise, the behavior of QmlSqlQuery is undefined.

See also QmlSqlDatabase and QmlSqlQueryModel.

Property Documentation

connectionName : string

Sets up the connectionName to match that of the QmlSqlDatabase. It is highly suggested that one uses the connection name.

errorString : string

Returns error information about the last error (if any) that occurred with this query.

lastQuery : string

Returns the text of the current query ( queryString ) being used, or an empty string if there is no current query text.

See also queryString and lastQueryOutPut.

lastQueryOutPut : string

Returns the text from the last query that was ran. If there was a error one can use errorString to retrive more information about the error,

See also errorString.

queryString : string

Sets the query to queryString that will be run on the connected QmlSqlDatabase via a connectionName. It is highly suggested to use a connectionName when running a query,

See also connectionName and QmlSqlDatabase.

Method Documentation

void exec()

Executes a previously prepared SQL query ( queryString ). on a connected QmlSqlDatabase via connectionName.

Note That the last error for this query is not reset when exec() is called.

void execWithQuery(string connectionName, string queryString)

Method that is used to execute SQL query. This method takes in two strings the first one being the connectionName and the second one being the SQL queryString that you wish to run.

Example:


  Column {
      anchors.fill: parent
      spacing: 1
      TextArea{
          id: output
          width:parent.width
          height : parent.height - ( queryTrigger.height * 2 + 4)
      }
      Button{
          text: "Clear"
          width:parent.width
          onClicked{
              output.text = ""
          }
      }
      Button{
          id: queryTrigger
          width:parent.width
          text: "Run SELECT * FROM SOMETABLE"
          onClicked{
              dbQueryRunner( "master-connection",  "SELECT * FROM SOMETABLE" )
          }
      }
  }

  QmlSqlQuery{
      id: dbQueryRunner
      onErrorStringChanged:{
          output.color = red
          output.text = errorString
          output.color = black
      }
      onDone: {
          output.text += lastQueryOutPut
      }
  }

Note The last error for this query is not reset when execWithQuery() is called.

See also QmlSqlDatabase, exec(), and connectionName.