Question

我有一个带有一些存储过程的Firebird数据库，我正在开发一个Java Web /数据库应用程序。我想知道是否可能以及如何从java类或Servlet调用这些存储过程。

示例：

存储过程deletep，用于从数据库中删除行
我的webapp Jsp / servlets
我想创建一个执行删除存储过程的链接

Answer 1

要在Java中执行Firebird存储过程，有几种方法。 JDBC默认方法类似于：

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    cstmt.execute();
}

如果Firebird存储过程是可选择的（即：包含SUSPEND并且可以返回多行），则需要执行以下操作：

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    try (ResultSet rs = cstmt.executeQuery()) {
        while(rs.next()) {
            // do something with result set rows ...
        }
    }
}

如果存储过程是可执行的并且不返回任何值，则这就足够了。如果存储过程可以使用（多个）返回列执行，则需要执行以下操作：

try (CallableStatement cstmt = connection.prepareStatement(
        "{call yourProcedure(?, ?, ?, ?, ?)}")) {
    cstmt.setString(1, "value1");
    cstmt.setString(2, "value2");
    cstmt.setString(3, "value3");
    cstmt.registerOutParameter(4, Types.VARCHAR);
    cstmt.registerOutParameter(5, Types.VARCHAR)
    cstmt.execute();

    String out1 = cstmt.getString(4);
    String out2 = cstmt.getString(5);
    // do something with result
}

或者，您可以将Firebird特定语法EXECUTE PROCEDURE yourProcedure(?, ?, ?)用于可执行存储过程和SELECT * FROM yourProcedure(?, ?, ?)。

Answer 2

使用Firebird JDBC驱动程序Jaybird可以实现这一点。

三个步骤：

创建一个DBUtil java类来存储查询：

public static void deletePlan(Connection conn, CallableStatement 
        statement, String code, String rev, String mention) throws SQLException {  

    statement.setString(1, code);
    statement.setString(2, rev);
    statement.setString(3, mention);
    statement.execute();
}

创建删除servlet

protected void doGet(HttpServletRequest request, 
        HttpServletResponse response) throws ServletException, IOException {
    Connection conn = MyUtils.getStoredConnection(request);

    String code = request.getParameter("code");
    String rev = request.getParameter("revision");
    String mention = request.getParameter("mention");
    CallableStatement statement = null;
    try {
        statement = conn.prepareCall("execute procedure 
    DELETEP(?,?,?)");
    } catch (SQLException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

    String errorString = null;

    try {
        DBUtils.deletePlan(conn, statement, code, rev, mention);
    } catch (SQLException e) {
        e.printStackTrace();
        errorString = e.getMessage();
    } 
    .........

在jsp文件中创建删除链接

<a href="${pageContext.request.contextPath}/deletePlan code=${plan.code}&revision=${plan.revision}&mention=${plan.mention}">Delete</a>

从Java Servlet

2 个答案: