What is JDBC?
Java API 1. is a method for executing SQL statements
2. It consists of a set of classes written in the Java language and interfaces
3.JDBC provides a standard method of operating a data
4.JDBC goal is to make Java programmers can connect to any JDBC driver provides a JDBC database system
By driving connection
The JDBC API
1. java.sql package is the JDBC API.
2. The major database vendors will provide implementation classes for the JDBC API - driver package
3. Be careful not to mistake the lead pack, do not refer to this class not to introduce com.mysql..Xxx
Java connect to MySQL
Add Drive
1. Create a file folder in which the project is lib
2. Copy Mysql driver package to the folder
3.builder path compiler path
Load the driver
The com.mysql.jdbc.Driver The JVM byte code loaded into
When a bytecode is loaded into the JVM, the static block of code will execute bytecode
JDK1.6 from the start without having to manually load the driver
Code Example:
Create a table operation MySql
1. Driver loading
2. Connect database
3. Create sql statement to be executed
Statement interface for executing a static SQL statement object
SQL statements sent to the database for execution. And returns the result of execution
1. For DQL query returns a result set
2. For DML returns the number of rows affected
3. For DDL returns 0
executeUpate(String)
DDL and DML statements execution
4. Execute the sql
The release of data resources
DML , query operation
DML operations and DDL operations are the same, only the sql statement occurred variables
Result set
ResultSet: shows the results of a database query of collections, in case of a query will get a result like this
Common method
boolean next (): determine whether there is a next row of data, if so, the cursor moves down one line.
getXxx (int columnIndex): Gets the current line, the first of several columns (starting at 1): not recommended
getXxx (String columnName): Gets the current row, column name specified column value .columnName a column name alias / column
If the column type is VARCHAR / CHAR / TEXT, use getString to get the value of the column.
If the column type is int / integer / -> getInt to get the value of the column.
Sql execution
executeQuery (Sql) will get a result set
Get a data:
Gets a row of data:
Get multiple rows of data
Before that I used 5.0.13 of the driver package, use the back of a driver package 8.0.15
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