Java insert modifies the basic method to delete database data
- 2020-04-01 04:14:26
- OfStack
Insert records for Java databases
There are three ways to insert data table records
1. Use Statement object
The syntax of the SQL statement to insert the data table record is:
insert into The name of the table ( The field name 1 The field name 2, ... )value ( The field values 1 Value of a field, 2 And... )
Such as:
insert into ksInfo( Test number, name, grade, address, resume )value( ' 200701',' zhang '534 . ' Ouyang road, Shanghai 218 get 4-1202','')
The Java program code to achieve the same function is:
sql = " insert intoksIno( Test number, name, grade, address, resume ) " ;
sql= = sq1+ " value( '" +txtNo.getTxt()+',' " +txtName.getText(0 " ', " ;
sql = sql+txtScore.getText();
sql=sql+ " ,' " +txtAddr.getText()+ " ',' " +txtResume.getText()+ " ') " ;
stmt.executeUpdate(sql);
Second, use a ResultSet object
MoveToInsertRow (), a method of the ResultSet object, moves the table cursor to the insertion position, and after entering the data, inserts the record with the method insertRow(). For example, here is the code:
String sql= " select * from ksInfo " ;//Generate SQL statements
ResultSet rs = stmt.executeQuery(sql);//Gets the data table result set
rs.moveToInsertRow();//Moves the data table cursor to the insertion record position
rs.updateString(1,'200701');//Fill in the test number field with data
rs.updateString(2,' zhang ');//Fill the name field with data
rs.updateInt(3,534);//Fill the grade field with data
rs.updateString(4,' Ouyang road, Shanghai 218 get 4-1202');//Fill the address field with data
rs.updateString(5,'');//Fill the resume field with data
try{rs.insertRow();}catch(Exception e){};//Complete the insert
Use a PrepareStatement object
Similar to the way you would use a Statement object, except that when you create an SQL Statement, you temporarily use parameters. Represents the value, then generates a PrepareStatement object from the SQL statement object, and updates the record by setting the actual parameters when inserting. The code is as follows:
sql = " insert into ksInfo( Test number, name, grade, address, resume )value (?,?,?,?,'') " ;
PrepareStatement pStmt = connect.prepareStatement(sql);
pStmt.setString(1,'200701');//Fill in the test number field with data
pStmt. setString (2,' zhang ');//Fill the name field with data
pStmt.setInt(3,534);//Fill the grade field with data
pStmt. setString (4,' Ouyang road, Shanghai 218 get 4-1202');//Fill the address field with data
pStmt. setString (5,'');//Fill the resume field with data
pStmt.executeUpdate();
There are three ways to insert data table records
1. Use Statement object
The syntax of the SQL statement to insert the data table record is:
insert into The name of the table ( The field name 1 The field name 2, ... )value ( The field values 1 Value of a field, 2 And... )
Such as:
insert into ksInfo( Test number, name, grade, address, resume )value( ' 200701',' zhang '534 . ' Ouyang road, Shanghai 218 get 4-1202','')
The Java program code to achieve the same function is:
sql = " insert intoksIno( Test number, name, grade, address, resume ) " ;
sql= = sq1+ " value( '" +txtNo.getTxt()+',' " +txtName.getText(0 " ', " ;
sql = sql+txtScore.getText();
sql=sql+ " ,' " +txtAddr.getText()+ " ',' " +txtResume.getText()+ " ') " ;
stmt.executeUpdate(sql);
Second, use a ResultSet object
MoveToInsertRow (), a method of the ResultSet object, moves the table cursor to the insertion position, and after entering the data, inserts the record with the method insertRow(). For example, here is the code:
String sql= " select * from ksInfo " ;//Generate SQL statements
ResultSet rs = stmt.executeQuery(sql);//Gets the data table result set
rs.moveToInsertRow();//Moves the data table cursor to the insertion record position
rs.updateString(1,'200701');//Fill in the test number field with data
rs.updateString(2,' zhang ');//Fill the name field with data
rs.updateInt(3,534);//Fill the grade field with data
rs.updateString(4,' Ouyang road, Shanghai 218 get 4-1202');//Fill the address field with data
rs.updateString(5,'');//Fill the resume field with data
try{rs.insertRow();}catch(Exception e){};//Complete the insert
Use a PrepareStatement object
Similar to the way you would use a Statement object, except that when you create an SQL Statement, you temporarily use parameters. Represents the value, then generates a PrepareStatement object from the SQL statement object, and updates the record by setting the actual parameters when inserting. The code is as follows:
sql = " insert into ksInfo( Test number, name, grade, address, resume )value (?,?,?,?,'') " ;
PrepareStatement pStmt = connect.prepareStatement(sql);
pStmt.setString(1,'200701');//Fill in the test number field with data
pStmt. setString (2,' zhang ');//Fill the name field with data
pStmt.setInt(3,534);//Fill the grade field with data
pStmt. setString (4,' Ouyang road, Shanghai 218 get 4-1202');//Fill the address field with data
pStmt. setString (5,'');//Fill the resume field with data
pStmt.executeUpdate();
Java database modification record
There are also three options for modifying data table records.
1. Use Statement object
The syntax of the SQL statement to modify the data table record is:
update The name of the table set The field name 1 = The field values 1 The field name 2 = The field values 2 And... where Certain conditions
Such as:
update ksInfo set The name = 'xiao-wei zhang 'where The name = "Zhang '
Start by creating an SQL Statement and then calling the executeUpdate() method of the Statement object. For example,
sql = " update ksInfo set The name = '" +txtName.getText();
sql = sql + " , results = " +txtScore.getText();
sql = sql + " , address =' " +txtAddr.getText();
sql= sql+ " ',, resume =' " +txtResume.getText()+ " 'where Candidate number = " +txtNo.getText();
stmt.executeUpdate(sql);
Second, use a ResultSet object
First set up the ResultSet object, then directly set the field value of the record, modify the record of the data table. For example,
String sql = " select * from ksInfo where The name =' zhang ' " ;//Generate SQL statements
ResultSet rs = stmt.executeQuery(sql);//Gets the data table result set
if(rs.next()){
rs.updateString(2,' Xiao-wei zhang ');
try{rs.updateRow();}catch(Exception e){}
}
Use a PrepareStatement object
When creating an SQL statement, temporarily use parameters? Represents the value, and then the PrepareStatement object is generated by the SQL statement object, which then updates the record by setting the actual parameters. Schematic code:
sql = " update ksInfo set The name =? where The name = "Zhang ';
PrepareStatement pStmt = connect.prepareStatement(sql);
pStmt.setString(2,' Xiao-wei zhang ');//Fill the name field with data
pStmt.executeUpdate();
Delete records for Java databases
There are also three options for deleting tables
1. Use Statement object
The syntax of the SQL statement that deletes the data table record is:
delete from The name of the table where Certain conditions
Such as:
delete from ksInfo where The name = "Zhang '
Create an SQL Statement, then call the Statement object's executeUpdate() method:
stmt.executeUpdate(sql);
Second, use a ResultSet object
You create an SQL Statement and then call the executeUpdate() method of the Statement object. Such as:
String sql = " select * from ksInfo where The name = "Zhang ' " ;//Generate SQL statements
ResultSet rs = stmt.executeQuery(sql);//Gets the data table result set
if(rs.next()){
rs.deleteRow();try{ rs.updateRow();}catch(Exception e){}
}
Use a PrepareStatement object
When creating an SQL statement, temporarily use parameters? Represents the value, and then the PrepareStatement object is generated by the SQL statement object, which then sets the actual parameters to achieve the deletion of a particular record. For example, here is the code:
sql = " delete form ksInfo where The name =? " ;
PrepareStatement pStmt = connect.prepareStatement(sql);
pStmt.setString(2,' zhang ');//Specify the data for the name field
pStmt.executeUpdate();