JDBC Common Memos

Jdbc

Contents of the JDBC Utils package

Performing a driver load in a static code block

Class.forName ("Com.mysql.jdbc.Driver");

Four private variables, which need to be modified when the database is different;

Private static final String username = "root";
Private static final String password = "root";
Private static final String URL = "Jdbc:mysql://localhost/mysql?seunicode=true&characterencoding=utf8";
private static final String drivername = "Com.mysql.jdbc.Driver";

Then encapsulated the ExecuteQuery (Connection conn,string sql,object...parameters)/executequery (sql,parameters)

Executeupdate (Connection conn,string sql,object...parameters)/executeupdate (sql,parameters)

and the corresponding close (conn/rs) method;

SQL additions and deletions change clause

SELECT * FROM table name

Select name from table name where conditional statement Name=value

Insert into table name (property name 1, property name 2 ...) values (attribute value 1, property value 2 ...);

Update table Name set Name=value, name2=value2 ... where condition statement;

Delete from table where Name=value

The total MySQL database Query method can be select COUNT (*) from  table (table name); Total: Select count as TotalCount from table1 summation: select sum (field1)  As Sumvalue from table1 average: Select AVG (field1) as Avgvalue from table1 maximum: select Max (field1) as MaxValue from table1 min: Select Min (field1) as MinValue from table1


Http://www.cnblogs.com/cunkouzh/p/5588319.html

JDBC Common Memos