oracle sql keywords list

: SELECT * FROM(SELECT z.type , z.code ,ROW_NUMBER()OVER(PARTITION BY z.type ORDER BY z.code) AS code_idFROM group_info z)WHERE code_id =1; The over () mentioned here is an oracle analysis function. Refer to the SQL reference document: Analytic functions compute an aggregate value based on a group of rows. They differ from aggregate functions in that they return multiple rows for each group.Analytic functi

Oracle PL/SQL Composite data types Composite data types can be roughly divided into two types. The first type is record type, which is suitable for processing single row and multiple columns of data, a bit similar to VO in java; the first type is set type, suitable for processing Single Column and multiple rows of data, similar to List in java, the following expe

speed.⑤ you can consider creating an index for a table that queries 2%~4% only from the total number of rows. The following are the basic principles of creating an index:(1) based on the query keyword, the rows in the table are randomly sorted.(2) A table containing a relatively small number of columns.(3) Most of the queries in the table contain relatively simple whrer clauses.(4) For tables that are often based on query keywords, and the rows in th

--oracle, "How do we deal with this problem?" I want to help, but my methods may have been wrong all along. Maybe I should write a summary to summarize some of the problems that may be involved. When other people ask me for help, I can give him the list of questions. If the person is receiving an ordinary Oracle initiation education, the

When using Oracle, you always encounter java. SQL. the SQLException error caused me to be exhausted on the Internet, so I checked several common ones in one breath and listed them here. english is from the official website. I have simply translated it in Chinese. Some people do not know how to translate it or try to reproduce it. So I will list the original Engli

1. Cursor Concept A swimming cursor is a handle or pointer to a context area. When you perform a crud operation in a pl/sql block, Oracle assigns the context area to it in memory. Using the database language to describe a cursor is a position entity that maps on a row of data in the context area result set. A user can use a cursor to access any row of data in the result set, and the row data is manipulat

Sql0668n cause code is "1 ", therefore, the SQL state = 57016 Oracle cannot be imported to db2sql0668n at a time because the cause code is "1" sqlstate = 57016 Oracle to DB2 Sun Moon King's blog http://sunmoonking.spaces.live.com using MTK tool failed to import data, so (Oracle uses MTK tool to import data to DB2 Http

Common commands and functions of Oracle SQL * plus, oracleplus Common commands: Connect to sqlplusRun cmd in the command line to enter. For example, to log on in sys mode, the command is as follows:(1). sqlplus "sys/zhb126 as sysdba" (2). sqlplus/nolog connect sys/zhb126 as sysdba (3). sqlplus scott/tiger Start a database instance Startup -- start the control file and data file while starting the database S

SQL execution is slow, how fast and accurate optimization. SQLHC is one of the best tools. By getting all the SQL execution plans, list the actual performance bottlenecks, listing the number of rows on the table where SQL resides, the data and distribution of each column, the existing index, the actual ex

1, do not use ' * ' instead of all column names, especially if the field is more than the caseUse SELECT * To list all column names for a table, but there is a dynamic parsing problem with Oracle. The Oracle system translates ' * ' into all column names of the table by querying the data dictionary, which naturally consumes system time.2, when the whole table is d

conjunction with or as a variety of the Case expression. Coalesce returns the first not null value in a given list of values. E. g.: returning the first not null value available in four columns present in a table. Select coalesce (col1, col2, col3, col4) from am25; E. g.: The above example will return the same result as the below statement with the case expression. Select case when col1 is not null then col1 when col2 is not null then col2 when c

Tags: ACK contact exp Payroll init Arch List Condition action 1 --Remove duplicate rows: Distinct 2 --scope: Is the combination of all subsequent fields 3 Select distinctDeptno Sal fromEMP;4 SELECT * fromEmpORDER bySal;5 --Condition of (date type) 6 SELECT * fromEmpWHEREHireDate='1 July-December on -80'; 7 --use a like fuzzy query (% for 0 or more characters, _ for one character, special characters for escape identifiers) 8 SELECT * fromEmpWHEREEn

DATABASE Archivelog ALTER DATABASE OPENView commands supported by Sqlplus Help INDEXUnlocking user Locks Executed with the user password set in the first step of installing Oracle (e.g., Sqlplus "sys/zhb126 as SYSDBA") Alter user Scott account unlock; Then execute Sqlplus scott/tiger, which will ask you to modify Scott's new password.Setting command line support spaces Set Sqlblanklines onVariable substitution-variable substitution-this process only

Tags: des blog http io ar os using SP forHttp://www.cnblogs.com/sopost/archive/2010/10/11/2190076.html in the SQL statement optimization process, we often use the hint, now summarize the SQL optimization process common Oracle Usage of hint:1./*+all_rows*/Indicates that the cost-based optimization method is selected for the statement block, and the optimal through