<?php

# 創(chuàng)建連接
$conn = mysqli_connect("localhost", "root", "admin", "study");

# 查看是否連接成功
if ($conn) {
    echo "服務(wù)器連接成功!";
} else {
    echo mysqli_connect_error();
}

# SQL語(yǔ)句 (身份證帶唯一性)
$SQL = "CREATE TABLE user_with_id (
    id INT(8) AUTO_INCREMENT PRIMARY KEY comment '主鍵id',
    username VARCHAR(255) NOT NULL comment '姓名',
    id_number varchar(255) UNIQUE NOT NULL comment '身份證號(hào)'
)";

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL);

# 查看是否執(zhí)行成功
if ($result) {
    echo "SQL語(yǔ)句執(zhí)行成功!";
} else {
    echo mysqli_error($conn);
}

# 關(guān)閉連接
mysqli_close($conn);

?>

<?php

# 創(chuàng)建連接
$conn = mysqli_connect("localhost", "root", "admin", "study");

# 查看是否連接成功
if ($conn) {
    echo "服務(wù)器連接成功!";
} else {
    echo mysqli_connect_error();
}

# SQL語(yǔ)句, 創(chuàng)建學(xué)生表
$SQL1 = "CREATE TABLE student (
    student_id INT(8) PRIMARY KEY COMMENT '學(xué)生id',
    student_name VARCHAR(255) NOT NULL COMMENT '學(xué)生姓名'
)";

# SQL語(yǔ)句, 創(chuàng)建成績(jī)表
$SQL2 = "CREATE TABLE grade (
    id INT(8) AUTO_INCREMENT PRIMARY KEY COMMENT '主鍵id',
    student_id INT(8) NOT NULL COMMENT '學(xué)生id',
    course varchar(255) NOT NULL COMMENT '課程',
    grade INT(8) NOT NULL COMMENT '成績(jī)',
    FOREIGN KEY (student_id) references student(student_id)
)";

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL1);

# 查看是否執(zhí)行成功
if ($result) {
    echo "SQL語(yǔ)句執(zhí)行成功!";
} else {
    echo mysqli_error($conn);
}

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL2);

# 查看是否執(zhí)行成功
if ($result) {
    echo "SQL語(yǔ)句執(zhí)行成功!";
} else {
    echo mysqli_error($conn);
}

# 關(guān)閉連接
mysqli_close($conn);

?>

<?php

# 創(chuàng)建連接
$conn = mysqli_connect("localhost", "root", "admin", "study");

# 查看是否連接成功
if ($conn) {
    echo "服務(wù)器連接成功!";
} else {
    echo mysqli_connect_error();
}

# SQL語(yǔ)句, 向主表添加數(shù)據(jù)
$SQL1 = "INSERT INTO student
    (student_id, student_name)
    VALUES(1, '我是小白呀'),
    (2, '我是大白呀')";

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL1);

# SQL語(yǔ)句, 向從表添加數(shù)據(jù)
$SQL2 = "INSERT INTO grade
    (student_id, course, grade)
    VALUES(1, '語(yǔ)文', 59),
    (2, '語(yǔ)文', 99)";

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL2);

# 查看是否執(zhí)行成功
if ($result) {
    echo "SQL語(yǔ)句執(zhí)行成功!";
} else {
    echo mysqli_error($conn);
}

# 關(guān)閉連接
mysqli_close($conn);

?>

<?php

# 創(chuàng)建連接
$conn = mysqli_connect("localhost", "root", "admin", "study");

# 查看是否連接成功
if ($conn) {
    echo "服務(wù)器連接成功!";
} else {
    echo mysqli_connect_error();
}

# SQL語(yǔ)句, 錯(cuò)誤展示 (主表沒(méi)有student_id=3)
$SQL = "INSERT INTO grade
    (student_id, course, grade)
    VALUES(3, '語(yǔ)文', 88)";

# 執(zhí)行SQL語(yǔ)句
$result = mysqli_query($conn, $SQL);

# 查看是否執(zhí)行成功
if ($result) {
    echo "SQL語(yǔ)句執(zhí)行成功!";
} else {
    echo mysqli_error($conn);
}

# 關(guān)閉連接
mysqli_close($conn);

?>