點解唔support? |
答題得分者是:yachanga
|
BorlandUser
中階會員 發表:148 回覆:217 積分:73 註冊:2004-02-19 發送簡訊給我 |
CREATE TABLE User
(
User_ID INT UNSIGNED NOT NULL AUTO_INCREMENT,
User_Name VARCHAR (50) NOT NULL,
Login_ID CHAR (20) NOT NULL,
Password CHAR (12) NOT NULL,
Version INT UNSIGNED NOT NULL,
Status TINYINT UNSIGNED NOT NULL,
Added_Date DATETIME NOT NULL,
Added_By INT UNSIGNED NOT NULL,
Updated_Date DATETIME NOT NULL,
Updated_By INT UNSIGNED NOT NULL, PRIMARY KEY (User_ID),
INDEX (Login_ID)
); CREATE TABLE Customer
(
Customer_ID INT UNSIGNED NOT NULL AUTO_INCREMENT,
Customer_Code CHAR (5) BINARY NOT NULL,
Customer_Name VARCHAR (50) NOT NULL,
Customer_Address VARCHAR (100) NOT NULL,
Contact_Tel VARCHAR (20) NOT NULL,
Contact_Fax VARCHAR (20) NOT NULL,
Contact_Email VARCHAR (50) NOT NULL,
Version INT UNSIGNED NOT NULL,
Status TINYINT UNSIGNED NOT NULL,
Added_Date DATETIME NOT NULL,
Added_By INT UNSIGNED NOT NULL,
Updated_Date DATETIME NOT NULL,
Updated_By INT UNSIGNED NOT NULL, PRIMARY KEY (Customer_ID),
INDEX (Customer_Code)
); procedure TMainUserForm.Button1Click(Sender: TObject);
var
strSQL: String;
begin
strSQL := 'Select Customer.Added_By, Customer.Updated_By, User.User_Name From Customer, User Where Customer.Added_By = User.User_ID';
ShowMessage(strSQL); With SQLQuery Do
Begin
Close;
SQL.Clear;
SQL.Add(strSQL);
Open; If (RecordCount = 1) Then
ShowMessage('Success');
End; end; 我錯左那裏,不能執行,我用sqlquery架,它說operation not support??
|
yachanga
資深會員 發表:24 回覆:335 積分:296 註冊:2003-09-27 發送簡訊給我 |
Hi BorlandUser:
這個問題之前很多大大討論過
Recordcount 使用上有很多限制ㄝ
替代方案很多,可以改成如下表示:
strSQL := 'Select count(*) CNT From Customer, User Where Customer.Added_By = User.User_ID'; With SQLQuery Do Begin Close; SQL.Clear; SQL.Add(strSQL); Open; If (FieldByName('CNT').asInteger = 1) Then ShowMessage('Success'); END;可參考如下Borland官方解釋 Question: Why am I getting the error 'Operation Not Supported' when calling TSQLQuery.RecordCount? This error may also be preceded by the exception'ORA-00942: table or view does not exist' in the IDE. Answer: You should note from the Delphi help that reading RecordCount will generate an exception if the dataset can not determine the number of records. Do not read RecordCount if: The dataset represents stored procedure. The dataset represents a query that contains parameters. The dataset represents a multi-table join. http://community.borland.com/article/0,1410,28494,00.html 發表人 - yachanga 於 2004/04/29 23:56:56 |
BorlandUser
中階會員 發表:148 回覆:217 積分:73 註冊:2004-02-19 發送簡訊給我 |
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