substr and instr together in oracle

Most of the questions raised in the Forum recently are related to column and column conversion. Therefore, I have summarized the knowledge of column and column conversion,I hope it will be helpful to you and make some mistakes at the same time.

Oracle String FunctionsRecently changed the new company, and back to the Oracle database, a lot of things have forgotten, just have an impression, these two nights smoked a bit of time, the oracle of the string of some processing functions to do a

[ Oracle-based SQL Optimization ]Oracle-based SQL optimization"Bo Master" Gao Ruilin"Blog Address" http://www.cnblogs.com/grl214 A Written Intent description In the early stage of the system development, due to less

This article will introduce some interesting functions that trisi often uses in daily life, or which are rarely used. There are two types of introduction: Famous functions-frequently used functions Non-famous functions-although rarely used, they are

--1, use month as conditional filter (to_char function and extract function)SELECT * from Test_date where To_char (DQSJ, ' mm ') like '%07% ';SELECT * from Test_date where extract (month from DQSJ) = 6;--2, get view nameSELECT * from User_views;--3,

Use a memory table to handle complex oracle query requirements. during daily business processing, we often encounter some unconventional query requirements. We can use dynamic statements or other existing oracle functions to complete the query

Oracle date functions: Months_between: returns the difference of the month between two dates months_between ('01-EP-95 ', '11-Jan-94') ==> 19.6774194 add_months: Number of copies added to the date. add_months ('11-Jan-94 ', 6) ==> '11-JUL-94'

Oracle date functions/character functions/numeric functions/conversion functions/Aggregate functions Oracle date functions: [SQL] MONTHS_BETWEEN: returns the difference of the month between two dates MONTHS_BETWEEN ('01-EP-95 ', '11-JAN-94 ') ==> 19.

PL/SQL single-row functions and group functions A function is a program with zero or multiple parameters and a return value. Oracle has a series of built-in functions in SQL, which can be called SQL or PL/SQL statements. functions are mainly divided

Oracle function list:========================================================== ========================================================== ==================================PL/SQL single-row functions and group functionsA function is a program with