oracle database sql expert certification

. NET provides four Database Connection Methods:System. Data. oledb. oledbconnectionSystem. Data. sqlclient. sqlconnectionSystem. Data. ODBC. odbcconnectionSystem. Data. oracleclient. oracleconnection Access: User ID = admin; Data Source = "/> Program Medium: connect "sqlconnstring" and "dbpath" to a conn_string_non_dtc"Public static readonly string conn_string_non_dtc = system. configuration. configurationmanager. appsettings ["sqlconnstring"]. tostr

Oracle Database Programming: dynamic SQL: it is a string at compile time, and it is only found to be an SQL statement at run time. When SQL statements cannot be used directly, dynamic SQL is used. dynamic

Tags: using data SP C size r database SQL BSPaged query statements that are used in different databases:Current page: CurrentPagePage Size: pagesize1. Oracle DatabaseSELECT * FROM (select A.*,rownum rn from (query_sql) A) where Rn Note: query_sql is a query SQL statement.OrSELECT * FROM (select RowNum rn,id from TABLEN

How to connect MySQL, Oracle, SQL Server database JDBC mysql: add a MySQL jar package first String url= "jdbc:mysql://localhost:3306/database name"; //Database address String name= "root";//database user name String password

Three database date conversions comparison:http://blog.csdn.net/zljjava/article/details/17552741SQL type conversion function: Cast (type1 as Type2)Date types in the database SQL SERVERDATE 1970-01-01DATETIME 1970-01-01 00:00:00OracleDATE 2015-08-07 17:34:37TIMESTAMP 1970-01-01 00:00:00.000000 is the extended type of date, with fractional secondsDate-to-string Ora

In general, Oracle databases operate more efficiently than SQL Server databases in large data environments. From the query optimization alone, the two are quite different. Below, the author of the database query optimization of the difference to do a description, if there is not accurate place, but also please criticize the advice. One, in the

1. SQL Server, Access database This is all Microsoft's database, is a family, the basic operation is similar, often using the following paging statement: PAGESIZE: Number of records displayed per page CurrentPage: Current page number The name of the datasheet is: components Index PRIMARY key word is: ID 以下是引用片段： select top PAGESIZE * from components where i

Use of Oracle Database [Entry edition, including common SQL statements]Enter sqlplus in the command promptOr directly open sqlplusScott/tiger (User Name/password) {or enter the user name (scott)-press ENTER-enter the password (tiger )}1. sqlplusA client tool provided by Orcale, which can be used to send some SQLCommunicate with the databaseSqlplus commandSqlplus

Oracle|sql server|access Database Tutorial All table names, field names SELECT * FROM user_tables WHERE table_name = ' username ' Use the following statement if you are logged on with this user:SELECT *From User_tables;If you are using another user:SELECT * from All_tables WHERE owner= ' user_name 'First, the first sentence: is the query of the user under all t

Sql%notfound is a Boolean value. Interacts with the most recent SQL statement (Update,insert,delete,select), which returns True when the most recent SQL statement does not involve any rows. Otherwise, false is returned. Such statements are useful in practical applications. For example, to update a row of data, if not found, you can do the appropriate action. Such

This article mainly introduces the PHP based on PDO database operation class, can achieve basic database connection, add and revise check, close connection and other operations, but also support for MySQL, SQL Server and Oracle database operations, the need for friends can r

Reprinted from: http://www.cnblogs.com/tianqing/archive/2008/06/25/1229419.htmlOracle database structure comparison, comparison of specific details of the differences, such as: 2 libraries specific to those tables, different where, the primary key, length, type ..., the requirement is a SQL implementation, for me, this SQL rookie, is a challenge. Fortunately, the

A virtual index is a "false" index, which is defined in a data dictionary, but does not have the corresponding index segment, that is, it does not allocate any storage space. Using Virtual indexes, developersYou do not need to wait for the index to be created, or you do not need additional index storage space, you can use it as an index that already exists and test the execution plan of the SQL statement. If the optimizer isThe execution plan for

Today with PL/SQL to connect to a database old report ora-12541: TNS: No listener error. Solution: Refer to the SQL * Plus User's Guide and reference for more information.[Oracle @ vserever75 ~] $ Sqlplus/nolog SQL * Plus: Release 10.2.0.4.0-production on Thu Apr 25 10:28:11

Install Oracle database management software SQL Developer in Ubuntu 14.04 This is the second article about building Oracle Development Environment logs. Article 1: Build a PHP5 + Apache2 + Oracle environment in Ubuntu 14.04 This article will install the

I read ArticleHe talked about how to import data from SQL Server to the SQL Server compact edition database. What I need now is to replace SQL with an Oracle database, and my Oracle Da

PL/SQL Connect Oracle Database 1, IntroductionUse PL/SQL to connect to a remote Oracle database without installing an Oracle database.2, the

Oracle Database PL/SQL process and function 4) process www.2cto.com 1. basic concept: oracle allows you to create and store compiled PL/SQL programs in the database, including processes, functions, packages, and triggers. We can s