如何從Firebird數據庫提示消息到C＃程序插入過程

我在這裏有一個firebird中的插入過程，它所做的是驗證我試圖保存的數據是否存在於表中。如果我試圖保存的數據存在於表格中，那麼數據將不會被保存。如果是這種情況，我將如何提示用戶數據不存在，因爲數據存在？如何從Firebird數據庫提示消息到C＃程序插入過程

這裏是我的插入過程

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;

這裏是我的C＃

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); 
      } 
     }

來源

2017-05-18 Don Juan

'SELECT COUNT（A.EMP_PK）' - 這是InterBase /火鳥相當糟糕的主意 –

您可以創建一個exception代碼。

CREATE EXCEPTION MY_EXCEPTION 'Exception text';

然後在存儲過程調用的異常，如果該數據有：

IF (EXSTING_EMP_PK = 0) THEN 
BEGIN 
    INSERT INTO TRAINTRN_TABLE (
    EMP_PK, 
    ..... 
END 
ELSE 
    EXCEPTION MY_EXCEPTION;

然後在C代碼中你可能會得到異常如常。

另一種方式：

剛剛從存儲過程返回一個結果，例如：

IF (EXSTING_EMP_PK = 0) THEN 
BEGIN 
    INSERT INTO TRAINTRN_TABLE (
    EMP_PK, 
    ..... 
    OUTPUT_RESULT = 1; 
END 
ELSE 
    OUTPUT_RESULT = 0; 

SUSPEND;

來源

2017-05-18 06:44:07

如何從Firebird數據庫提示消息到C＃程序插入過程

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