我在火鸟中有一个插入过程,它的作用是验证我尝试保存的数据是否存在于表中。如果我尝试保存的数据存在于表中,则不会保存数据。如果是这种情况,我将如何提示用户由于数据存在而未保存数据?
这是我的插入程序
CREATE PROCEDURE TRAINTRN_INSERT(
EMP_PK INTEGER,
TRAINTRN_EMP_TYPE VARCHAR(50) CHARACTER SET ISO8859_1 COLLATE ISO8859_1,
TRAINTRN_BATCH VARCHAR(50) CHARACTER SET ISO8859_1 COLLATE ISO8859_1,
TRAINTRN_AREA VARCHAR(100) CHARACTER SET ISO8859_1 COLLATE ISO8859_1,
TRAINTRN_SRCVCRDT DECIMAL(12, 2),
TRAINING_PK INTEGER,
USER_PK SMALLINT,
TRAINTRN_UPDATETIME TIMESTAMP)
AS
DECLARE VARIABLE EXSTING_EMP_PK INTEGER;
DECLARE VARIABLE EXSTING_TRAINING_PK INTEGER;
BEGIN
FOR
SELECT
COUNT(A.EMP_PK)
FROM TRAINTRN_TABLE A WHERE A.TRAINING_PK =: TRAINING_PK AND A.EMP_PK =: EMP_PK
INTO
:EXSTING_EMP_PK
DO
IF (EXSTING_EMP_PK = 0) THEN
BEGIN
INSERT INTO TRAINTRN_TABLE (
EMP_PK,
TRAINTRN_EMP_TYPE,
TRAINTRN_BATCH,
TRAINTRN_AREA,
TRAINTRN_SRCVCRDT,
TRAINING_PK,
USER_PK,
TRAINTRN_UPDATETIME)
VALUES (
:EMP_PK,
:TRAINTRN_EMP_TYPE,
:TRAINTRN_BATCH,
:TRAINTRN_AREA,
:TRAINTRN_SRCVCRDT,
:TRAINING_PK,
:USER_PK,
CURRENT_TIMESTAMP);
END
END;
这是我的 C# 代码
var adder = new ClsHR();
adder.SaveParticipants();
XtraMessageBox.Show("Successfully Added.", "Save ",
MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
public void SaveParticipants()
{
try
{
var adder = new FbConnection(ClsConnection.FirebirdSQL);
var fbcmd = new FbCommand("TRAINTRN_INSERT", adder)
{
CommandType = CommandType.StoredProcedure
};
fbcmd.Parameters.Add("@EMP_PK", FbDbType.VarChar).Value = UpdtHndlrEmp;
fbcmd.Parameters.Add("@TRAINTRN_EMP_TYPE", FbDbType.VarChar).Value = TRAINTRN_EMP_TYPE;
fbcmd.Parameters.Add("@TRAINTRN_BATCH", FbDbType.VarChar).Value = TRAINTRN_BATCH;
fbcmd.Parameters.Add("@TRAINTRN_AREA", FbDbType.VarChar).Value = TRAINTRN_AREA;
fbcmd.Parameters.Add("@TRAINTRN_SRCVCRDT", FbDbType.VarChar).Value = TRAINTRN_SRCVCRDT;
fbcmd.Parameters.Add("@TRAINING_PK", FbDbType.VarChar).Value = UpdateHandler;
fbcmd.Parameters.Add("@USER_PK", FbDbType.SmallInt).Value = ClsEmployee.USER_PK;
fbcmd.Parameters.Add("@TRAINTRN_UPDATETIME", FbDbType.VarChar).Value = EventTimestamp;
fbcmd.Connection.Open();
fbcmd.ExecuteNonQuery();
fbcmd.Connection.Close();
}
catch (Exception errorcode)
{
XtraMessageBox.Show(String.Format("Error in connection: {0}. Saving failed.", errorcode.Message), @"Server Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
}
您可以创建异常。
CREATE EXCEPTION MY_EXCEPTION 'Exception text';
然后在存储过程中,如果数据存在,则调用异常:
IF (EXSTING_EMP_PK = 0) THEN
BEGIN
INSERT INTO TRAINTRN_TABLE (
EMP_PK,
.....
END
ELSE
EXCEPTION MY_EXCEPTION;
然后在 C 代码中,您可能会像往常一样获得异常。
另一种方式:
只需从存储过程返回结果,例如:
IF (EXSTING_EMP_PK = 0) THEN
BEGIN
INSERT INTO TRAINTRN_TABLE (
EMP_PK,
.....
OUTPUT_RESULT = 1;
END
ELSE
OUTPUT_RESULT = 0;
SUSPEND;