ExecuteNext(IDataReader) Method

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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: 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 = @"if object_id('dept', 'U') is not null drop table dept; CREATE TABLE Dept( DEPTNO int PRIMARY KEY NOT NULL, DNAME varchar(14) NULL, LOC varchar(13) NULL );"+ "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"; SqlConnection myConn = new SqlConnection( "User Id=sa;Server=localhost;Initial Catalog=Test;"); SqlScript myScript = new SqlScript(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();

string script =
  @"if object_id('dept', 'U') is not null
  drop table dept;
CREATE TABLE Dept(
  DEPTNO int PRIMARY KEY NOT NULL,
  DNAME varchar(14) NULL,
  LOC varchar(13) NULL
);"+
  "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";
SqlConnection myConn = new SqlConnection(
    "User Id=sa;Server=localhost;Initial Catalog=Test;");
SqlScript myScript = new SqlScript(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 = _ "if object_id('dept', 'U') is not null" & _ " drop table dept;" & _ "CREATE TABLE Dept(" & _ " DEPTNO int PRIMARY KEY NOT NULL," & _ " DNAME varchar(14) NULL," & _ " LOC varchar(13) NULL" & _ ");" & _ "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 SqlConnection = New SqlConnection( _ "User Id=sa;Server=localhost;Initial Catalog=Test;") Dim myScript As SqlScript = New SqlScript(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()

Dim script As String = _
  "if object_id('dept', 'U') is not null" & _
  "  drop table dept;" & _
  "CREATE TABLE Dept(" & _
  "  DEPTNO int PRIMARY KEY NOT NULL," & _
  "  DNAME varchar(14) NULL," & _
  "  LOC varchar(13) NULL" & _
  ");" & _
  "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 SqlConnection = New SqlConnection( _
    "User Id=sa;Server=localhost;Initial Catalog=Test;")
Dim myScript As SqlScript = New SqlScript(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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