add questions

data/2.Java中阶/4.使用JDBC操作数据库/1.JDBC概述/Abstract.md

@@ -7,7 +7,7 @@
 ## 答案
 
 ```
-
+JDBC只可以用来建立数据库的连接
 ```
 
 ## 选项

data/2.Java中阶/4.使用JDBC操作数据库/1.JDBC概述/DriverType.json

+{
+    "type": "code_options",
+    "author": "clong",
+    "source": "DriverType.md",
+    "exercise_id": "",
+    "notebook_enable": true
+}
\ No newline at end of file

data/2.Java中阶/4.使用JDBC操作数据库/1.JDBC概述/DriverType.md

+# JDBC Driver Type
+
+
+以下不属于JDBC驱动类型的是：
+
+
+## 答案
+
+```
+JDBC-TCP
+```
+
+## 选项
+
+### A
+
+```
+JDBC-ODBC桥驱动
+```
+
+### B
+
+```
+JDBC-Native API
+```
+
+### C
+
+```
+JDBC-Net
+```

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/CRUD.json

+{
+    "type": "code_options",
+    "author": "clong",
+    "source": "CRUD.md",
+    "exercise_id": "",
+    "notebook_enable": true
+}
\ No newline at end of file

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/CRUD.md

+# JDBC CRUD
+
+
+以下对数据库的操作错误的是：
+
+
+## 答案
+
+```java
+import java.sql.*;
+
+public class CRUD {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            String sql = "drop FROM student where id = 1";
+            stmt.executeQuery(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+## 选项
+
+### A
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class CRUD {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            String sql = "INSERT INTO student " +
+                    "VALUES (1, '小明', '男', 18)";
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### B
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class CRUD {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            String sql = "UPDATE student " +
+                    "SET age = 15 WHERE id = 1";
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### C
+
+```java
+import java.sql.*;
+
+public class CRUD {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            String sql = "SELECT id, name, sex, age FROM student where id = 1";
+            ResultSet rs = stmt.executeQuery(sql);
+            while(rs.next()){
+                int id  = rs.getInt("id");
+                int age = rs.getInt("age");
+                String name = rs.getString("name");
+                String sex = rs.getString("sex");
+                System.out.println("id:" + id + ",name:" + name + ",sex" + sex + ",age:" + age);
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/PSQLConnection.json

+{
+    "type": "code_options",
+    "author": "clong",
+    "source": "PSQLConnection.md",
+    "exercise_id": "",
+    "notebook_enable": true
+}
\ No newline at end of file

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/PSQLConnection.md

+# PSQL Connection
+
+
+以下连接postgre数据正确的是：
+
+
+## 答案
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class PSQLConnection {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/test", "root", "root");
+            Statement stmt = conn.createStatement();
+
+            String sql = "CREATE TABLE student " +
+                    "(id INTEGER not NULL, " +
+                    " name VARCHAR(255), " +
+                    " sex VARCHAR(255), " +
+                    " age INTEGER, " +
+                    " PRIMARY KEY ( id ))";
+
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+## 选项
+
+### A
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class PSQLConnection {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/test");
+            Statement stmt = conn.createStatement();
+
+            String sql = "CREATE TABLE student " +
+                    "(id INTEGER not NULL, " +
+                    " name VARCHAR(255), " +
+                    " sex VARCHAR(255), " +
+                    " age INTEGER, " +
+                    " PRIMARY KEY ( id ))";
+
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### B
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class PSQLConnection {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://root:root@localhost:5432/test");
+            Statement stmt = conn.createStatement();
+
+            String sql = "CREATE TABLE student " +
+                    "(id INTEGER not NULL, " +
+                    " name VARCHAR(255), " +
+                    " sex VARCHAR(255), " +
+                    " age INTEGER, " +
+                    " PRIMARY KEY ( id ))";
+
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### C
+
+```java
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class PSQLConnection {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://localhost/test", "root", "root");
+            Statement stmt = conn.createStatement();
+
+            String sql = "CREATE TABLE student " +
+                    "(id INTEGER not NULL, " +
+                    " name VARCHAR(255), " +
+                    " sex VARCHAR(255), " +
+                    " age INTEGER, " +
+                    " PRIMARY KEY ( id ))";
+
+            stmt.executeUpdate(sql);
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/Transaction.json

+{
+    "type": "code_options",
+    "author": "clong",
+    "source": "Transaction.md",
+    "exercise_id": "",
+    "notebook_enable": true
+}
\ No newline at end of file

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/Transaction.md

+# Transaction
+
+
+以下关于事务的写法能达到出错回退的目的的是：
+
+
+## 答案
+
+```java
+import java.sql.*;
+
+public class Transaction {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            try {
+                conn.setAutoCommit(false);
+                String insertSQL = "INSERT INTO student " +
+                        "VALUES (1, '小明', '男', 18)";
+                stmt.executeUpdate(insertSQL);
+                String updateSQL = "UPDATE student " +
+                        "SET age = 15 WHERE id = 1";
+                stmt.executeUpdate(updateSQL);
+                String deleteSQL = "delete FROM student where id = 1";
+                stmt.executeUpdate(deleteSQL);
+                conn.commit();
+            } catch (SQLException e) {
+                conn.rollback();
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+## 选项
+
+### A
+
+```java
+import java.sql.*;
+
+public class Transaction {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            try {
+                String insertSQL = "INSERT INTO student " +
+                        "VALUES (1, '小明', '男', 18)";
+                stmt.executeUpdate(insertSQL);
+                String updateSQL = "UPDATE student " +
+                        "SET age = 15 WHERE id = 1";
+                stmt.executeUpdate(updateSQL);
+                String deleteSQL = "delete FROM student where id = 1";
+                stmt.executeUpdate(deleteSQL);
+                conn.commit();
+            } catch (SQLException e) {
+                conn.rollback();
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### B
+
+```java
+import java.sql.*;
+
+public class Transaction {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            try {
+                String insertSQL = "INSERT INTO student " +
+                        "VALUES (1, '小明', '男', 18)";
+                stmt.executeUpdate(insertSQL);
+                String updateSQL = "UPDATE student " +
+                        "SET age = 15 WHERE id = 1";
+                stmt.executeUpdate(updateSQL);
+                String deleteSQL = "delete FROM student where id = 1";
+                stmt.executeUpdate(deleteSQL);
+            } catch (SQLException e) {
+                conn.rollback();
+            }
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```
+
+### C
+
+```java
+import java.sql.*;
+
+public class Transaction {
+    public static void main(String[] args) throws ClassNotFoundException, SQLException {
+        Connection conn = null;
+        try {
+            Class.forName("org.postgresql.Driver");
+            conn = DriverManager.getConnection("jdbc:postgresql://192.168.126.76:5432/ask_classifier", "csdn", "csdn");
+            Statement stmt = conn.createStatement();
+            conn.setAutoCommit(false);
+            String insertSQL = "INSERT INTO student " +
+                    "VALUES (1, '小明', '男', 18)";
+            stmt.executeUpdate(insertSQL);
+            String updateSQL = "UPDATE student " +
+                    "SET age = 15 WHERE id = 1";
+            stmt.executeUpdate(updateSQL);
+            String deleteSQL = "delete FROM student where id = 1";
+            stmt.executeUpdate(deleteSQL);
+            conn.commit();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            if (conn != null) {
+                conn.close();
+            }
+        }
+    }
+}
+```

data/2.Java中阶/4.使用JDBC操作数据库/2.数据库操作/config.json

@@ -98,6 +98,6 @@
       }
     }
   ],
-  "export": [],
+  "export": ["PSQLConnection.json", "CRUD.json", "Transaction.json"],
   "title": "数据库操作"
 }
\ No newline at end of file