java的String類型可以讀取mysql裏的int類型參數。
public class jdbcFunction {
public void getInformation(String Gradename){
Connection c=null;
Statement s=null;
ResultSet rs=null;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url="jdbc:mysql://localhost:3306/test?serverTimezone=UTC";
c= DriverManager.getConnection(url,"root","wangjun");
String test="SELECT * FROM `grade1`" +
"WHERE GradeID="+Gradename+";";
s=c.createStatement();
rs=s.executeQuery(test);
while(rs.next()){
String id =rs.getString("gradeid");//這裏的gradeid在mysql裏是int類型;
String grade=rs.getString("gradename");
System.out.println(id+"\t\t"+grade);
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}finally {
try {
rs.close();
s.close();
c.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
jdbcFunction j=new jdbcFunction();
j.getInformation("4");
}
}
https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-reference-type-conversions.html
通常,任何MySQL數據類型都可以轉換爲a java.lang.String,並且任何數字類型都可以轉換爲任何Java數字類型,但可能會出現舍入,溢出或精度損失。