java如何在MySQL中向表中插入变量

Question

我知道如何将数据添加到表中。就像

String insertQuery = "INSERT INTO tablename (x_coord, y_coord)"
                            +"VALUES"
                            +"(11.1,12.1)";
s.execute(insertQuery);

11.1和12.1可以插入表中。现在给出一个浮点变量

float fv = 11.1;

如何将fv插入表中

Answer 1

在JAVA中，您可以使用如下准备好的语句：

Connection conn = null;
PreparedStatement pstmt = null;

float floatValue1 = 11.1;
float floatValue2 = 12.1;

try {
    conn = getConnection();
    String insertQuery = "INSERT INTO tablename (x_coord, y_coord)"
                        +"VALUES"
                        +"(?, ?)";
    pstmt = conn.prepareStatement(insertQuery);
    pstmt.setFloat(1, floatValue1);
    pstmt.setFloat(2, floatValue2);
    int rowCount = pstmt.executeUpdate();
    System.out.println("rowCount=" + rowCount);
} finally {
    pstmt.close();
    conn.close();
}

Answer 2

我建议您使用Prepared Statement，如下所示：

final PreparedStatement stmt = conn.prepareStatement(
        "INSERT INTO tablename (x_coord, y_coord) VALUES (?,?)");
stmt.setFloat(1, 11.1f);
stmt.setFloat(2, 12.1f);
stmt.execute();