-- Sentence skill
-- Data Operations
SELECT -- retrieve data rows and columns from database tables
INSERT -- add new data rows to the database table
DELETE -- DELETE data rows from a database table
UPDATE -- UPDATE data in the database table
-- Data
-- Sentence skill
1. Data OperationsSelect -- retrieve data rows and columns from database tablesInsert -- add new data rows to the database tableDelete -- delete data rows from a database tableUpdate -- update data in the database table
2.
Comparison of common functions for SQL Server to Oracle
1. Absolute ValueS: Select ABS (-1) ValueO: Select ABS (-1) value from dual
2. INTEGER (large)S: Select ceiling (-1.001) ValueO: Select Ceil (-1.001) value from dual
3. Round (small)S: Select
Previously, I wanted to record some of the usual functions of SQL, but it has not been implemented ... Hey...Until today, the substring () function is used, and in C # The starting value of this method is 0, and the starting value in SQL is 1. Silly
String functionsstring comparison functionsIf the length of the result is greater than the maximum value of the Max_allowed_packet system variable, the return value of the string value function is null. See section 7.5.2, "Tuning server parameters."
String function string comparison function if the result length is greater than the maximum value of the max_allowed_packet system variable, the return value of the string value function is NULL. See section 7.5.2 "Adjust server Parameters ".
String
Generally, the entire string is used as the operation object, for example: search for a substring in a substring, obtain a substring, insert a substring at a certain position in the substring, and delete a substring.
Generally, the entire string is
A string or string (string) is a finite sequence consisting of 0 or more characters. Generally recorded as s= ' a1a2 an ' (n>=0). It is the data type that represents text in the programming language.
A string is usually used as an action object,
Generally, the entire string is used as the operation object, for example: search for a substring in a substring, obtain a substring, insert a substring at a certain position in the substring, and delete a substring. The required and sufficient
String is a finite sequence composed of zero or multiple characters. It is generally recorded as s = 'a1a2 • an '(n> = 0 ). It is the data type that represents text in programming languages.Generally, the entire string is used as the operation
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.