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 DEPT;"+
  "CREATE TABLE DEPT ("+
  "  DEPTNO INT PRIMARY KEY,"+
  "  DNAME VARCHAR(14),"+
  "  LOC VARCHAR(13)"+
  ")WITH OIDS;"+
  "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";
PgSqlConnection pgConn = new PgSqlConnection(
    "host=server;database=test;user id=postgres;");
PgSqlScript pgScript = new PgSqlScript(script,pgConn);
IDataReader pgReader;
pgConn.Open();
while (pgScript.ExecuteNext(out pgReader))
{
  Console.WriteLine("Records affected " + pgReader.RecordsAffected); 
  while (pgReader.Read()) 
  { 
    Console.WriteLine(pgReader.GetString(0)); 
  } 
  pgReader.Close(); 
}
pgConn.Close();

Visual Basic

Dim script As String = _
  "DROP TABLE DEPT;" & _
  "CREATE TABLE DEPT (" & _
  "  DEPTNO INT PRIMARY KEY," & _
  "  DNAME VARCHAR(14)," & _
  "  LOC VARCHAR(13)" & _
  ")WITH OIDS;" & _
  "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 pgConn As PgSqlConnection = New PgSqlConnection( _
    "host=server;database=test;user id=postgres;")
Dim pgScript As PgSqlScript = New PgSqlScript(script, pgConn)
Dim pgReader As IDataReader
pgConn.Open()
While (pgScript.ExecuteNext(pgReader))
  Console.WriteLine("Records affected " & pgReader.RecordsAffected)
  While pgReader.Read()
    Console.WriteLine(pgReader.GetString(0))
  End While
  pgReader.Close()
End While
pgConn.Close()

Reference

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

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