我有一个批处理程序,用于使用JDBC调用数据库。 我使用'ID'作为主键发送一批100个信息。如何使用Java执行多个SQL语句?
我想对数据库进行一次调用,然后在关闭连接之前执行多个SQL语句。
我参考
// Database credentials
String USER = username;
String PASS = password;
Connection connec = null;
Statement stmt = null;
//STEP 2: Register JDBC driver
Class.forName("com.mysql.jdbc.Driver");
//STEP 3: Open a connection
System.out.println("Connecting to a selected database...");
connec = DriverManager.getConnection(DB_URL, USER, PASS);
System.out.println("Connected database successfully...");
//STEP 4: Execute a query
System.out.println("Creating statement...");
stmt = connec.createStatement();
// Step 2: To update the database with the new count and the netppe values.
// Step to know whether the ID is present or not in the database
for(int i=0;i<identities.length;i++){
String booleanString = "SELECT 1 FROM cgm_counters WHERE id = "+identities[i];
stmt.execute(booleanString);
ResultSet resultSet = stmt.getResultSet(); //result set for records
boolean recordFound = resultSet.next();
ResultSet rs = null;
// Retrieve the 'netppe' information.
if(recordFound){
String sql = "SELECT * FROM cgm_counters WHERE id="+identities[i];
rs = stmt.executeQuery(sql);
while(rs.next()){
//Retrieve by column name
double net_ppe = rs.getDouble("spend");
System.out.println("The value of the netppe :"+net_ppe);
}
}// end of 'If' statement
我想for循环做的三件事一气呵成每个ID在发布代码的部分。
1 > I want to see whether the ID is present or not in the database
2 > If ID - present
{
2 a > retrieve the 'netppe' information for that particular ID
2 b > retrieve the 'count' information for that same ID
2 c> Update the database with the new 'netppe' and 'count' value for the same ID
} else {
Insert the information for the new ID
}
如何执行所有语句而不必关闭每个ID的连接? JDBC和SQL的新手。任何帮助表示赞赏。
使用jdbc批处理。 – Kick
为什么你需要关闭每个ID的连接?你没有没有关闭连接的代码吗? – eis
@eis删除了'rs.close()'语句,并且如果我没有关闭连接并执行多个语句,那么相同的步骤会工作吗? – user3188390