Summary of where,having Filtration method

a where filter 1 Make with and and the OR Combining query Criteria

SELECT * from Sell WHERE sell_price>=1000 and (or) sell_price<=2000

2 To make use of. between and the Not between Filter Records

SELECT * from sell where sell_price between and a (notbetween is not in this range )

3. Use the inch and the not in Filter Records

SELECT * from the worker WHERE work_id in (' 9601 ', ' 9702 ') (not in is not this ...) Range

4 To make use of. like and wildcard filter Records

% has 0 or more characters-single character

[] Specify a range such as "a~f" [^] outside the specified range [^a~f]

? example, from "WORKER" find the name in the first two words is " ? text " staff information.

Select * from worker Where Work_name like ' _ text _ '

? Example: Query worker All employee information of Wang in the table

Select * FROM student Where student_name like ' Wang % '

? the employee information of duress surname Wang

Select * from the worker Where work_name like ' [ Liu Wang ]% '

? example, from "Worker" the lowest number of search job numbers in the table is not in 2~6 within the scope of the staff.

SELECT * from worker where work_id like '%[^2-6] '

5 To filter records with null values

SELECT * from supplier where Sup_tel are (not) null

Two having filter

Total number of employees with sales totals above $1000 and sales totals

Select Word_id,sum (sell_price) from sell where Sell_price > the group by word_id

Where filtering is the first to select the sales price above 1000, and then group the summary

Select Word_id,sun (sell_price) from sell GROUP by word_id have sum (sell_price) >1000

Having a filter is the first group summary, and then select the total sales of more than 1000

Different points:
1 WHERE Check that every record is full? having Check that the aggregated data for each group after the group rollup is full? sufficient conditions;
2 youcan use aggregate functions in the HAVING clause, but not in the whereclause.  

Where,having Filtering Method Summary