ExecuteNext(IDataReader) Method

In This Topic

Executes the next statement from the script.

Syntax

Visual Basic
C#

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

public bool ExecuteNext( 
   out IDataReader reader
)

Parameters

reader: Devart.Common.DbDataReader 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()

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

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

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