2020年6月2日

    1. <?php
    2. try{
    3. $dsn="mysql:host=127.0.0.1;port=3306;dbname=liuyan;charset=utf8";
    4. $pdo=new PDO($dsn,"root","root"); 
    5.   //准备sql语句
    6. //$sql ="INSERT INTO books VALUES(2,'茄子',110)"; //增
    7. //$sql="DELETE FROM books WHERE book_id=1";             //删
    8. $sql="UPDATE books SET title='我起了一枪秒了'";    //改
    9. $res=$pdo->exec($sql);
    10. if($res){
    11. echo "操作成功" .$res;
    12. }else{
    13. echo "操作失败";
    14. }
    16.  $sql="SELECT * FROM books";
    18. $res=$pdo->query($sql);
    19. if($res){
    20. echo"执行成功";
    21. $fetch_data[];
    22.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    23.   $fetch_data[]=$row;
    25.   }
    26.   var_dump($fetch_data);
    27. }else{
    28. echo "执行失败";
    29. } 
    30. }catch(PDDException $e){
    31. var_dump($e->getMessage());
    32. }
    34. $sql="SELECT * FROM books";
    36. $res=$pdo->query($sql);
    37. if($res){
    38. echo"执行成功";
    39. $fetch_data[];
    40.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    41.   $fetch_data[]=$row;
    43.   }
    44.   var_dump($fetch_data);
    45. }else{
    46. echo "执行失败";
    47. }
    51. <?php
    52. try{
    53. $dsn="mysql:host=127.0.0.1;port=3306;dbname=liuyan;charset=utf8";
    54. $pdo=new PDO($dsn,"root","root"); 
    55.   //准备sql语句
    56. //$sql ="INSERT INTO books VALUES(2,'茄子',110)"; //增
    57. //$sql="DELETE FROM books WHERE book_id=1";             //删
    58. $sql="UPDATE books SET title='我起了一枪秒了'";    //改
    59. $res=$pdo->exec($sql);
    60. if($res){
    61. echo "操作成功" .$res;
    62. }else{
    63. echo "操作失败";
    64. }
    66.  $sql="SELECT * FROM books";
    68. $res=$pdo->query($sql);
    69. if($res){
    70. echo"执行成功";
    71. $fetch_data[];
    72.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    73.   $fetch_data[]=$row;
    75.   }
    76.   var_dump($fetch_data);
    77. }else{
    78. echo "执行失败";
    79. } 
    80. }catch(PDDException $e){
    81. var_dump($e->getMessage());
    82. }
    84. $sql="SELECT * FROM books";
    86. $res=$pdo->query($sql);
    87. if($res){
    88. echo"执行成功";
    89. $fetch_data[];
    90.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    91.   $fetch_data[]=$row;
    93.   }
    94.   var_dump($fetch_data);
    95. }else{
    96. echo "执行失败";
    97. }
    100. <?php
    101. try{
    102. $dsn="mysql:host=127.0.0.1;port=3306;dbname=liuyan;charset=utf8";
    103. $pdo=new PDO($dsn,"root","root"); 
    104.   //准备sql语句
    105. //$sql ="INSERT INTO books VALUES(2,'茄子',110)"; //增
    106. //$sql="DELETE FROM books WHERE book_id=1";             //删
    107. $sql="UPDATE books SET title='我起了一枪秒了'";    //改
    108. $res=$pdo->exec($sql);
    109. if($res){
    110. echo "操作成功" .$res;
    111. }else{
    112. echo "操作失败";
    113. }
    115.  $sql="SELECT * FROM books";
    117. $res=$pdo->query($sql);
    118. if($res){
    119. echo"执行成功";
    120. $fetch_data[];
    121.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    122.   $fetch_data[]=$row;
    124.   }
    125.   var_dump($fetch_data);
    126. }else{
    127. echo "执行失败";
    128. } 
    129. }catch(PDDException $e){
    130. var_dump($e->getMessage());
    131. }
    133. $sql="SELECT * FROM books";
    135. $res=$pdo->query($sql);
    136. if($res){
    137. echo"执行成功";
    138. $fetch_data[];
    139.   while($row=$res->fetch(PDO::FETCH_ASSOC)){
    140.   $fetch_data[]=$row;
    142.   }
    143.   var_dump($fetch_data);
    144. }else{
    145. echo "执行失败";
    146. }

    笔记
    $dsn结构
    每个结构用;分隔开
    1.数据源名（myself）
    2.安装地址(主机名)(host)
    3.端口(port)默认3306
    4.数据库名称(dbname)
    5.编码(charset) 常用UTF8

    PDO执行增删改操作
    步骤：
    1，准备sql语句
    2，执行sql语句
    当语句执行失败的时候回返回false；通常是语句写错了或者是表名写错了

    结果类别
    PDO::FETCH_ASSOC 结果设置未关联数组

    PDO::FETCH_BOTH 结果只为混合数组
    PDO::FETCH_NUM 结果只为索引数组