crossplatform---Nodejs in Visual Studio Code 07.学习Oracle

1.开始

Node.js：https://nodejs.org

OracleDB: https://github.com/oracle/node-oracledb/blob/master/INSTALL.md#instwin

　　　　　 https://github.com/oracle/node-oracledb/blob/master/doc/api.md#resultsethandling

2.OracleDB安装

• Python 2.7

　　下载安装即可，略

• C Compiler with support for C++ 11 (Xcode, gcc, Visual Studio or similar)

　　打开Visual Studio的安装文件，查看C编译器是否安装，见下图

• The small, free Oracle Instant Client "basic" and "SDK" packages if your database is remote. Or use a locally installed database such as the free Oracle XE release

　　打开Oracle Instant Client，免费下载basic和sdk两个压缩包，绿色软件无须安装

　　instantclient-basic-windows.x64-12.1.0.2.0.zip  69MB

　　instantclient-sdk-windows.x64-12.1.0.2.0.zip   2.62MB

　　将两个ZIP文件解压到同一个目录中Z:\Softs\OracleClient\12GX64

• Set OCI_LIB_DIR and OCI_INC_DIR during installation if the Oracle libraries and headers are in a non-default location

　　打开我的电脑->属性->高级属性->环境变量，新增两个环境变量ORACLE_HOME64,OCI_LIB_DIR 和 OCI_INV_DIR

　　ORACLE_HOME64 : Z:\Softs\OracleClient\12GX64

　　OCI_LIB_DIR : %ORACLE_HOME64%\sdk\lib\msvc

　　OCI_INV_DIR : %ORACLE_HOME64%\sdk\include

　　将Z:\Softs\OracleClient\12GX64这个路径%ORACLE_HOME64%加到Path中。

• 执行CMD命令

1	$ npm install oracledb

3.OracleDB普通查询

dbconfig.js 配置数据库连接字符串

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

module.exports = {   user          : process.env.NODE_ORACLEDB_USER || "test",     // Instead of hard coding the password, consider prompting for it,   // passing it in an environment variable via process.env, or using   // External Authentication.   password      : process.env.NODE_ORACLEDB_PASSWORD || "test",     // For information on connection strings see:   // https://github.com/oracle/node-oracledb/blob/master/doc/api.md#connectionstrings   connectString : process.env.NODE_ORACLEDB_CONNECTIONSTRING || "192.168.1.100/orcl",     // Setting externalAuth is optional.  It defaults to false.  See:   // https://github.com/oracle/node-oracledb/blob/master/doc/api.md#extauth   externalAuth  : process.env.NODE_ORACLEDB_EXTERNALAUTH ? true : false };

app.js执行一个简单的查询语句

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

var oracledb = require('oracledb'); var dbConfig = require('./dbconfig.js');   //打开一个链接 oracledb.getConnection(   {     user          : dbConfig.user,     password      : dbConfig.password,     connectString : dbConfig.connectString   },   function(err, connection)   {     if (err) {       console.error(err.message);       return;     }     //执行查询语句     connection.execute(       "SELECT department_id, department_name " +         "FROM departments " +         "WHERE manager_id < :id",       [110],  // bind value for :id       { maxRows: 10 },  // a maximum of 10 rows will be returned.  Default limit is 100       function(err, result)       {         if (err) {           console.error(err.message);           doRelease(connection);           return;         }         console.log(result.metaData);         console.log(result.rows);         //查询结束后记得释放链接资源         doRelease(connection);       });   });   function doRelease(connection) {   connection.release(     function(err) {       if (err) {         console.error(err.message);       }     }); }

　　

4.OracleDB ResultSet查询

　　 普通查询，默认最大返回100条数据，如果需要查询更多的数据那么需要建立一个DataReader和数据库保持连接然后一行一行的读取数据，这个在nodejs oracledb里面就叫ResultSet查询。

你可以这样使用ResultSet，每次返回一行数据

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

connection.execute(   "SELECT employee_id, last_name FROM employees ORDER BY employee_id",   [], // no bind variables   { resultSet: true }, // return a result set.  Default is false   function(err, result)   {     if (err) { . . . }     fetchOneRowFromRS(connection, result.resultSet);   }); });   . . .   function fetchOneRowFromRS(connection, resultSet) {   resultSet.getRow( // get one row     function (err, row)     {       if (err) {          . . .           // close the result set and release the connection       } else if (!row) { // no rows, or no more rows         . . .            // close the result set and release the connection       } else {         console.log(row);         fetchOneRowFromRS(connection, resultSet);  // get next row       }     }); }

当然也可以每次返回多行数据，请使用numRows参数

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

var numRows = 10;  // number of rows to return from each call to getRows()   connection.execute(   "SELECT employee_id, last_name FROM employees ORDER BY employee_id",   [], // no bind variables   { resultSet: true }, // return a result set.  Default is false   function(err, result)   {     if (err) { . . . }     fetchRowsFromRS(connection, result.resultSet, numRows);   }); });   . . .   function fetchRowsFromRS(connection, resultSet, numRows) {   resultSet.getRows( // get numRows rows     numRows,     function (err, rows)     {       if (err) {          . . .                        // close the result set and release the connection       } else if (rows.length == 0) {  // no rows, or no more rows         . . .                         // close the result set and release the connection       } else if (rows.length > 0) {         console.log(rows);         fetchRowsFromRS(connection, resultSet, numRows);  // get next set of rows       }     }); }

http://www.cnblogs.com/mengkzhaoyun/p/5405912.html