如何将在JDBC中执行的SQL查询的结果分配给java变量？

Question

I have a student table with columns email, password, and a variable Result which can either hold a value "pass" or "fail". I'm executing this statement first in java using JDBC to find the result of a particular student when their email is passed.

String sql = "SELECT result FROM hr.student WHERE email = '"+email+"'";

conn = getConnection();
stmt = conn.prepareStatement(sql);

The value returned will either be "pass" or "fail". I want to store the returned value in a variable to use it for an if-else statement. (if result is "pass", --statements-- else --statements--)

How do I do this?

Answer 1

You can do it like :

ResultSet rs = stmt.executeQuery(sql);
String result = null;
if (rs.next()) { // replace 'if' with 'while' to iterate if multiple records
    result = rs.getString("result");
}

if you have more records, you can replace if with while and can iterate over ResultSet .

For the complete working example you can go through the example here.

Answer 2

I'd recommend to create the prepared statement as follows:

String sql = "SELECT result FROM hr.student WHERE email = ?";
conn = getConnection();
stmt = conn.prepareStatement(sql);
stmt.setString(1,email)

and then proceed as shown above