[英]Retrieve auto_increment value of multiple rows from MySQL in batch mode
有一個主鍵為id int auto_increment
的mysql表,我需要使用多個insert
語句批量插入多個行,並禁用autocommit
,如下所示:
SET autocommit=0;
INSERT INTO dummy(NAME, `size`, create_date) VALUES('test', 1, NOW());
INSERT INTO dummy(NAME, `size`, create_date) VALUES('test', 2, NOW());
COMMIT;
是否可以獲取每個生成的ID,而不僅僅是最后一個ID。
如果是,則每個ID何時生成,以及如何通過jdbc
獲取所有ID?
謝謝。
如果要通過JDBC檢索AUTO_INCREMENT密鑰,則需要使用JDBC功能( RETURN_GENERATED_KEYS
和.getGeneratedKeys()
),如下所示:
try (Connection conn = DriverManager.getConnection(myConnectionString, "root", "beer")) {
try (Statement st = conn.createStatement()) {
st.execute(
"CREATE TEMPORARY TABLE dummy (" +
"`id` INT AUTO_INCREMENT PRIMARY KEY, " +
"`NAME` VARCHAR(50), " +
"`size` INT, " +
"`create_date` DATETIME " +
")");
}
conn.setAutoCommit(false);
System.out.println("AutoCommit is OFF.");
String sql = "INSERT INTO dummy(NAME, `size`, create_date) VALUES('test', ?, NOW())";
try (PreparedStatement ps = conn.prepareStatement(
sql,
PreparedStatement.RETURN_GENERATED_KEYS)) {
// first batch
ps.setInt(1, 1); // `size` = 1
ps.addBatch();
ps.setInt(1, 2); // `size` = 2
ps.addBatch();
ps.executeBatch();
System.out.println("First batch executed. The following AUTO_INCREMENT values were created:");
try (ResultSet rs = ps.getGeneratedKeys()) {
while (rs.next()) {
System.out.println(rs.getInt(1));
}
}
try (Statement st = conn.createStatement()) {
sql = "SELECT COUNT(*) AS n FROM dummy";
try (ResultSet rs = st.executeQuery(sql)) {
rs.next();
System.out.println(String.format("The table contains %d row(s).", rs.getInt(1)));
}
}
conn.rollback();
System.out.print("Transaction rolled back. ");
try (Statement st = conn.createStatement()) {
sql = "SELECT COUNT(*) AS n FROM dummy";
try (ResultSet rs = st.executeQuery(sql)) {
rs.next();
System.out.println(String.format("The table contains %d row(s).", rs.getInt(1)));
}
}
// second batch
ps.setInt(1, 97); // `size` = 97
ps.addBatch();
ps.setInt(1, 98); // `size` = 98
ps.addBatch();
ps.setInt(1, 99); // `size` = 99
ps.addBatch();
ps.executeBatch();
System.out.println("Second batch executed. The following AUTO_INCREMENT values were created:");
try (ResultSet rs = ps.getGeneratedKeys()) {
while (rs.next()) {
System.out.println(rs.getInt(1));
}
}
}
try (Statement st = conn.createStatement()) {
sql = "SELECT COUNT(*) AS n FROM dummy";
try (ResultSet rs = st.executeQuery(sql)) {
rs.next();
System.out.println(String.format("The table contains %d row(s).", rs.getInt(1)));
}
}
}
...產生以下控制台輸出:
AutoCommit is OFF.
First batch executed. The following AUTO_INCREMENT values were created:
1
2
The table contains 2 row(s).
Transaction rolled back. The table contains 0 row(s).
Second batch executed. The following AUTO_INCREMENT values were created:
3
4
5
The table contains 3 row(s).
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