oracle sql functions

'Select Replace('000123','0') fromDual--The returned result is ' 123 ' NOTE: Omit the parameter replacement_string, replace the character ' 0 ' with null, i.e. delete all characters ' 0 '4. String connectionconcat (string1, string2) or ||Cases:Select concat (','World' from dual; -- returns the result as ' Hello world ' Select ' '| | ' World ' from dual; -- returns the result as ' Hello world '5. Get the string lengthLength (String)Cases:Select Length ('from- - Returns a result of 76, stri

server process session ID of the current user process. @ @SPID can identify the current user process in sp_who output results.ExampleThe following example returns the process ID, login name, and user name of the current user process. SELECT @ @SPID as ' ID ' System_user as ' Login Name ' USER as ' User Name ' Here is the result set: ID Login Name User Name ----- ------------- ----------- 11 sa dbo [Email protected] @VERSION amp;amp;amp;amp;amp

Tags: http io sp CTI on C SQL R BSWhere is the Oracle SQL Developer connection information saved?Oracle SQL Developer connection information is missing after switching the logged-on user. As long as the previous user information still exists, you can C:\Users\ the user name

is the number of strings returned, and if this number is shorter than the length of the original string, the Lpad function will intercept the string as a left-to-right n character;Pad_stringOptional parameter, this string is to be pasted to the right of the string, if this argument is not written, the Lpad function will paste a space on the right side of the string.Rpad (' Tech ', 7); will return ' tech 'Rpad (' Tech ', 2); will return ' Te 'Rpad (' Tech ', 8, ' 0 '); will return ' tech0000 'Rp

,=3000 when sale value =1000 translation to a , if other values are translated as other;SQL is as follows:Select Monthid,decode (sale,1000, ' D ', +, ' C ', +, ' B ', 4000, ' A ', ' other ') sale from outputSpecial cases:If you are comparing with only one valueSelect Monthid, decode (sale, NULL, '---', sale) sale from outputAnother: Decode can use other functions, such as the NVL function or the sign () fun

Question: Collect Oracle knowledge points that are commonly used at work, constantly update and accumulate, and use them as your own notebook. Some keywords 1Is not null. Check whether the field is null. Select*FromT_user uWhereU.NameIsNotNull 2 Case when... THEN... ELSE... END, Condition Statement SELECTCASEWHEN'Condition'ISNOTNULLTHEN'Condition exist'ELSE'The condition is invalid'ENDASResultFROMT_user 3 EXITS, not exits, to determine whet

)Lowercase ConversionIdle> select lower ('abc') from dual; LOW---Abc Idle>Dual is a virtual table. When a statement does not need to obtain data from the table but maintains the SQL syntax, Oracle provides a virtual table to solve this problem. UPPER (column name | expression)Capital Conversion Idle> select upper ('abc') from dual; UPP---ABC Idle> INITCAP (column name | expression)Uppercase and lowercase le

Character TypeASCIICHRLOWERUPPERINITCAPCONCATSUBSTRLENGTHINSTRTRIMDumpLpadRpadREPLACEASCII ('characters ')Returns the ASCII value of a character.Idle> select ASCII ('A') from dual;ASCII ('A ')----------97 Idle> select ASCII ('A') from dual; ASCII ('A ')----------65 Idle> CHR ('n ')Returns the character value n of n, which is the ASCII number.Idle> select chr (65) from dual; C-A Idle> select chr (39) from dual; C-' Idle> However, the ASCII code format for single quotes is very special. There are

Tag: SQL Server SQL data MySQLThis article introduces the ISNULL functions in SQL Server, as well as the ifnull functions in MySQL, describes the specific usage and differences between the two, interested friends can study oh.First look at the IsNull function of

Tags: tun pre use statement Scala RAM data stun CALInline table-valued functionsConnect to T-SQL programming-user-defined functions (scalar functions) Http://www.cnblogs.com/viusuangio/p/6212072.html 　　Inline table-valued functions can be used to implement parameterized views (queries), such as having a query whose de