oracle sql for dummies

Oracle SQL Language DDL and Object Management-beyond OCP proficient in Oracle Video tutorial training 27This course introduces:Oracle Video tutorial, wind Brother this set of Oracle Tutorial training is the Oracle SQL language DDL

Reposted from: longtang Bay 1.1.1 obtain the first N records SQL Server: Select Top N * From xtable ORACLE: Select * From xtable where rownum DB2: Select * From xtable fetch first n rows only 1.1.2 obtain the current date SQL Server: Select getdate () ORACLE: Select sysdate from dual DB2: Select current timestamp from

the return value VAR salary number; exec:salary:=get_sal (7369); PRINT salary; Mode two: Call function directly in SQL statement SELECT get_sal (7369) from DUAL; way three: Use Dbms_output call function SET serveroutput on EXEC Dbms_output.put_line (' Wages are: ' | | get_sal (7369));Delete functions drop function get_sal; Create a PackageA package is a PL/SQL structure that can store related o

Oracle uses AWR's SQL ordered by Gets and SQL ordered by Reads to diagnose problems I have read many database reports before, and have encountered two serious performance problems recently. They are very representative, so I recorded them. Once, the Oracle process is reported to get the CPU of the database server to 10

principle, the connection between tables must be written to the left of other where conditions , and those conditions that can filter out the maximum number of records must be written to the right of the WHERE clause .Example: Query employee's number, name, salary, department nameSelect Emp.empno,emp.ename,emp.sal,dept.dname from emp,dept where (Emp.deptno = Dept.deptno) and (Emp.sal > 1 500)Avoid using the * number in the SELECT clauseDuring the parsing process,

SQL Server Replace Null:isnull (Arg,value) For example: Select IsNull (price,0.0) from orders, if Price is null, replace with 0.0 Compared to null: is not null,is null For example, select * from to orders where price is null and price equals NULL such as: SELECT * from Orders where, "not NULL", price does not equal null Oracle Replace NULL:NVL (Arg,value) such as: Select NVL (price,0.0) Form orders

Tags: style http io os for strong data on HTML Database type Hibernate SQL dialect DB2 Org.hibernate.dialect.DB2Dialect DB2 as/400 Org.hibernate.dialect.DB2400Dialect DB2 OS390 Org.hibernate.dialect.DB2390Dialect PostgreSQL 8.1 Org.hibernate.dialect.PostgreSQL81Dialect PostgreSQL 8.2 and later Org.hibernate.dialect.PostgreSQL82Dialect

Tags: calculate high-precision modified address EFI struct arithmetic uname table structureSQL queries and SQL functions 　　This chapter aims 　　　　Understanding Oracle Data Types Understanding Data Definition Languages and data manipulation languages Understanding Transaction Control Languages and Data Control languages Mastering SQL Operators and

Oracle|sql Language Oracle Pl/sql Language Foundation 2002-8-23 Oracle Pl/sql Language Basics Pl/sql is Oracle's extension of the standard database language,

How to check whether the SQL statements are correct when executing large SQL statements in Oracle stored procedures? A large SQL statement is sometimes used in the preparation of a stored procedure in Oracle. However, you cannot see the

triggersA. Enabling and disabling triggers: When to prohibit: Prohibit data import and exportsql> ALTER TRIGGER aiu_itemfile DISABLE;sql> ALTER TRIGGER aiu_itemfile ENABLE;B. recompiling a trigger: After a database object has changedC. Deleting a triggersql> DROP TRIGGER Aiu_itemfile;19. Triggers and stored proceduresTrigger Stored proceduresWrite no parameter, return value has parameter, return value (parameter)Write cannot commit or rollback canCal

When you are running an SQL statement very slowly, do you want to ask Oracle how to execute this statement? The SQL _TRACE tool provided by Oracle allows you to know exactly what the SQL statement you run is. The execution process will be output to the trace file. The follow

Oracle SQL query optimization for Oracle Data Scanning (2) 2. How to improve the performance of local range data scanning: 2.1 category and role of query conditions: When we initiate a SQL statement with conditions, multiple query conditions are usually assigned to the statement. Among these query conditions, one or m

Troubleshooting of SQL plus logon failures caused by su switching in Oracle Problem description:The Oracle database in the production environment suddenly fails to log on, and the oracle database in the rlwrap production environment suddenly fails to log on. rlwrap sqlplus "/as sysdba" reports the following error: rlwr

Oracle queries the average SQL Execution time (Code instance) through the v $ SQL view, oraclesqlOracle queries the average SQL Execution time (Code instance) through the v $ SQL View) SELECT SQL _TEXT, EXECUTIONS total EXECUTIONS

The ORACLE tutorial is the basics of Oracle PL/SQL language. PL/SQL is an extension of ORACLE's standard database language. ORACLE has integrated PL/SQL into ORACLE servers and other to

Tags: character dev large database information Management DBA needs to run develop fromI. Classification of databases I. Classification of databases1. Small database: Access, Foxbase2. Medium database: Informix, SQL Server, MySQL3. Large database: Sybase, DB2, Oracle Second, how to reasonably use the database in the project, can be based on the following three aspects to start1, the size of the projectA, h

The Oracle tutorial you are looking at is the introductory Foundation for Oracle Pl/sql languages. Pl/sql is Oracle's extension of the standard database language, Oracle has integrated PL/SQL into

1. Oracle Introduction Oracle is the first word for English translation of oracle (Oracle bone inscriptions) Unearthed from Yin.. Oracle is the world's largest supplier of information management software and services. It was founded in 1977 and is headquartered in Redwood sh

Oracle Export Import table (. SQL,. dmp file) two methods,. SQL. dmp Two ways to export an import table (. SQL and. dmp files) from Oracle Method 1: Export and Import SQL files Export procedure 5. Select the table for data export