ExecuteNext(IDataReader) Method

In This Topic

Syntax
Remarks
Example
See Also

Executes the next statement from the script.

Syntax

Visual Basic
C#

public bool ExecuteNext( 
   out IDataReader reader
)

'Declaration
 
Public Function ExecuteNext( _
   ByRef reader As IDataReader _
) As Boolean

Parameters

reader: DbDataReaderBase to store result set.

Return Value

true if there are more statements to execute; otherwise, false.

Remarks

Use ExecuteNext method to execute the statements from the script one by one. Text of the script should be specified by ScriptText property.

After the method has executed the Progress event fires where you can obtain statement text and process query results. If the statement has produced an error, event Error fires.

To restart execution from the beginning of the script call Reset method. When ScriptText property is modified DbScript automatically positions on the first statement.

Example

This sample demonstrates how to execute script and retrieve information about how many records were affected by a statement. For statements that return a result set the first column is written to console.

csharp

string script =
  "DROP TABLE IF EXISTS DEPT;"+
  "CREATE TABLE DEPT ("+
  "  DEPTNO INT PRIMARY KEY,"+
  "  DNAME VARCHAR(14),"+
  "  LOC VARCHAR(13)"+
") TYPE = InnoDB;"+
  "INSERT INTO DEPT VALUES (10,'ACCOUNTING','NEW YORK');"+
  "INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS');"+
  "INSERT INTO DEPT VALUES (30,'SALES','CHICAGO');"+
  "INSERT INTO DEPT VALUES (40,'OPERATIONS','BOSTON');"+
  "SELECT * FROM DEPT";
MySqlConnection myConn = new MySqlConnection(
    "User Id=root;Host=localhost;Database=Test;");
MySqlScript myScript = new MySqlScript(script,myConn);
IDataReader myReader;
myConn.Open();
while (myScript.ExecuteNext(out myReader))
{
  Console.WriteLine("Records affected " + myReader.RecordsAffected); 
  while (myReader.Read()) 
  { 
    Console.WriteLine(myReader.GetString(0)); 
  } 
  myReader.Close(); 
}
myConn.Close();

Visual Basic

Dim script As String = _
  "DROP TABLE IF EXISTS DEPT;" & _
  "CREATE TABLE DEPT (" & _
  "  DEPTNO INT PRIMARY KEY," & _
  "  DNAME VARCHAR(14)," & _
  "  LOC VARCHAR(13)" & _
  ") TYPE = InnoDB;" & _
  "INSERT INTO DEPT VALUES (10,'ACCOUNTING','NEW YORK');" & _
  "INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS');" & _
  "INSERT INTO DEPT VALUES (30,'SALES','CHICAGO');" & _
  "INSERT INTO DEPT VALUES (40,'OPERATIONS','BOSTON');" & _
  "SELECT * FROM DEPT"
Dim myConn As MySqlConnection = New MySqlConnection( _
    "User Id=root;Host=localhost;Database=Test;")
Dim myScript As MySqlScript = New MySqlScript(script, myConn)
Dim myReader As IDataReader
myConn.Open()
While (myScript.ExecuteNext(myReader))
  Console.WriteLine("Records affected " & myReader.RecordsAffected)
  While myReader.Read()
    Console.WriteLine(myReader.GetString(0))
  End While
  myReader.Close()
End While
myConn.Close()

Reference

DbScript Class
DbScript Members
ScriptText Property
Execute Method
Progress Event
Error Event

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