CallableStatement 對象爲所有的DBMS 提供了一種以標準形式調用已儲存過程的方法。已儲 存過程儲存在數據庫中。對已儲存過程的調用是 CallableStatement對象所含的內容。這種調用是 用一種換碼語法來寫的,有兩種形式:一種形式帶結果參,另一種形式不帶結果參數。結果參數是 一種輸出 (OUT) 參數,是已儲存過程的返回值。兩種形式都可帶有數量可變的輸入(IN 參數)、 輸出(OUT 參數)或輸入和輸出(INOUT 參數)的參數。問號將用作參數的佔位符。
1.帶?參數的使用prepareStatement。這也是使用最多的。
public void addCategory(Category category) {
String sql = "insert into category values(seque_cid.nextval,?,?)";
PreparedStatement pstmt = null;
try {
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, category.getCname());
pstmt.setString(2, category.getCdesc());
pstmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
//關閉
if(pstmt!=null){
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
public void addCategory(Category category) {
String sql = "insert into category values(seque_cid.nextval,?,?)";
PreparedStatement pstmt = null;
try {
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, category.getCname());
pstmt.setString(2, category.getCdesc());
pstmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
//關閉
if(pstmt!=null){
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
2.不帶參數,例如查所用,不需要到任何參數。使用statement。
public List<Category> getAllCategorys() {
List<Category>list = new ArrayList<Category>();
String sql = "select * from category ";
Category c = null;
Statement stmt = null;
ResultSet rs = null;
try {
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
while(rs.next()){
c = new Category();
c.setCid(rs.getInt(1));
c.setCname(rs.getString(2));
c.setCdesc(rs.getString(3));
list.add(c);
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
//關閉
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(stmt!=null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
return list;
}
3.調用存儲過程的CallableStatement。
特別注意,存儲過程的輸出參數需要先進行註冊
public void callProcedure() {
String sql = "{call proce_bigger(?,?,?,?)}";
CallableStatement cstmt = null;
try {
cstmt = conn.prepareCall(sql);
cstmt.setInt(1, 10);
cstmt.setInt(2, 13);
cstmt.registerOutParameter(3, Types.INTEGER);
cstmt.registerOutParameter(4, Types.INTEGER);
cstmt.setInt(4, 6);
cstmt.executeUpdate();
System.out.println(cstmt.getInt(3));
System.out.println(cstmt.getInt(4));
} catch (Exception e) {
e.printStackTrace();
}finally{
//關閉
if(cstmt!=null){
try {
cstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
1 使用不帶參數的存儲過程
public static void executeStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{calldbo.GetContactFormalNames}");
ResultSetrs = cstmt.executeQuery();
while (rs.next()) {
System.out.println(rs.getString("FormalName"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
rs.close();
cstmt.close();
}
}
2 使用帶有輸入參數的存儲過程
public static void executeStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{call dbo.uspGetEmployeeManagers(?)}");
cstmt.setInt(1, 50);
ResultSetrs = cstmt.executeQuery();
while (rs.next()) {
System.out.println("EMPLOYEE:");
System.out.println(rs.getString("LastName") + ", "
+ rs.getString("FirstName"));
System.out.println("MANAGER:");
System.out.println(rs.getString("ManagerLastName") + ", "
+ rs.getString("ManagerFirstName"));
System.out.println();
}
}
catch (Exception e) {
e.printStackTrace();
} finally {
rs.close();
cstmt.close();
}
}
3 使用帶有輸出參數的存儲過程
public static void executeStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{call dbo.GetImmediateManager(?, ?)}");
cstmt.setInt(1, 5);
cstmt.registerOutParameter(2, java.sql.Types.INTEGER);
cstmt.execute();
System.out.println("MANAGER ID: " + cstmt.getInt(2));
} catch (Exception e) {
e.printStackTrace();
}
}
4 使用帶有返回狀態的存儲過程(目前測試狀態返回只能是int類型)
作爲示例,在 SQL Server 2005 AdventureWorks 示例數據庫中創建以下存儲過程:
CREATE PROCEDURE CheckContactCity @cityNameCHAR(50)ASBEGIN IF ((SELECT COUNT(*) FROM Person.Address WHERE City = @cityName) > 1) RETURN 1ELSE RETURN 0ENDpublic static void executeStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{? = call dbo.CheckContactCity(?)}");
cstmt.registerOutParameter(1, java.sql.Types.INTEGER);
cstmt.setString(2, "Atlanta");
cstmt.execute();
System.out.println("RETURN STATUS: " + cstmt.getInt(1));
}
catch (Exception e) {
e.printStackTrace();
}finally{
cstmt.close();
}
}
注:在sql中執行該存儲過程的方法: declare @c int
exec @c=CheckContactCity 'Atlanta' print @c
5 使用帶有更新記數的存儲過程
作爲示例,在 SQL Server 2005 AdventureWorks 示例數據庫中創建以下表和存儲過程:
CREATE TABLE TestTable (Col1 int IDENTITY, Col2 varchar(50), Col3 int);
CREATE PROCEDURE UpdateTestTable
@Col2 varchar(50), @Col3 int AS BEGIN
UPDATE TestTable
SET Col2 = @Col2, Col3 = @Col3 END;
public static void executeUpdateStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{call dbo.UpdateTestTable(?, ?)}");
cstmt.setString(1, "A");
cstmt.setInt(2, 100);
cstmt.execute();
int count = cstmt.getUpdateCount();
System.out.println("ROWS AFFECTED: " + count);
} catch (Exception e) {
e.printStackTrace();
}finally{
cstmt.close();
}
}
public static void executeUpdateStoredProcedure(Connection con) {
try {
CallableStatementcstmt = con
.prepareCall("{call dbo.UpdateTestTable(?, ?)}");
cstmt.setString(1, "A");
cstmt.setInt(2, 100);
cstmt.execute();
int count = cstmt.getUpdateCount();
System.out.println("ROWS AFFECTED: " + count);
} catch (Exception e) {
e.printStackTrace();
}finally{
cstmt.close();
}
}
附加說明
JDBC調用存儲過程: CallableStatement
在Java裏面調用存儲過程,寫法那是相當的固定: Class.forName(....
Connection conn = DriverManager.getConnection(.... /**
*p是要調用的存儲過程的名字,存儲過程的4個參數,用4個?號佔位符代替 *其餘地方寫法固定 */
CallableStatementcstmt = conn.prepareCall("{call p(?,?,?,?)}"); /**
*告訴JDBC,這些個參數,哪些是輸出參數,輸出參數的類型用java.sql.Types來指定
*下面的意思是,第3個?和第4個?是輸出參數,類型是INTEGER的 *Types後面具體寫什麼類型,得看你的存儲過程參數怎麼定義的
*/
cstmt.registerOutParameter(3, Types.INTEGER); cstmt.registerOutParameter(4, Types.INTEGER); /**
*在我這裏第1個?和第2個?是輸入參數,第3個是輸出參數,第4個既輸入又輸出
*下面是設置他們的值,第一個設爲3,第二個設爲4,第4個設置爲5 *沒設第3個,因爲它是輸出參數 */
cstmt.setInt(1, 3); cstmt.setInt(2, 4); cstmt.setInt(4, 5); //執行
cstmt.execute();
//把第3個參數的值當成int類型拿出來 int three = cstmt.getInt(3); System.out.println(three);
//把第4個參數的值當成int類型拿出來 int four = cstmt.getInt(4); System.out.println(four);
//用完別忘給人家關了,後開的先關 cstmt.close(); conn.close();
JDBC調用存儲過程,掌握這一個程序足夠了.
以下是上面程序使用的存儲過程的代碼,我用的是Oracle數據庫,不過不論是什麼數據庫,對於你
的程序,JDBC這一端寫法都是一樣的. create or replace procedure p
(v_a in number,v_bnumber,v_ret out number,v_temp in out number) is begin
if(v_a>v_b) then v_ret := v_a; else v_ret := v_b;
end if; v_temp := v_temp + 1; end;