One discovery question: 1 [User] - [Off] - [Check] Always go wrong, prompts Table 5 Closed; (Solved) Solution: Table5.avcive: = Ture; 2 Why is the database function in the source program At the time before opening, you will have a time. Such as: mmdataModule.ClientDataSet1.active: = false; mmdataModule.clientDataSet1.active: = TRUE
II Solved question: 1 Locate the main display reason: procedure tmmdataModule.timer1timer (sender: TOBJECT); begin mainform.statusbar1.panels [1] .text: = datetimetostr (now); gddlform.statusbar1. PANELS [1] .text: = DateTimetostr (now); end; 2 Using the TQuery components General Format: query1.close; // Turn off the dataset query1.sql.clear; // Clear Query1.sql.add ('SELECT * FROM domain name where data = "01"); // Add SQL statement query1.open; // Open data set, execute two dates in the SQL statement 3 Access database, such as (2000-1-1, 2010-1-1), the number of days between: function daysbetween (const no, athen: tdatetime): Integer; 4 Understand the use of controls in several source programs: [Statistics] button is mainly used. The "aggregate" field of the clientDataSet control: The relationship between the controls is as follows: [Revenue Management] - DBGRID3 - Datasource12 ClientDataSet7 -> DataSetProvider4
