2014.9.3 database Crud

CRUD Additions and deletions change

DCL Data Control Language: Backup,Grant

DML Data Manipulation language: CRUD

DDL Data Definition language:create drop alter

Self-growing columns cannot be assigned a value

Increase:

Insert into table name values(' ', ' ', ' ', ' ', ')--into can be omitted

By deleting:

Delete from table name (with log) (slow) truncate table name (does not write log, next execution self-growth column starts from 1 ) (FAST)

Delete from table where column name relationship operator value

Change:

Update table from set column name = value, column name = value,... , where Column name relational operator value

Check:

Select * from table

Select column name, column name,... from table

Select * from table where column name relational operator value and column name relational operator value

Select * from table where column between ten and (range query)

Select * from column where column in (3,4,5)

Select distinct column from table (column to weight)

Select * from car where name is like%5%% any number of arbitrary characters;_ an arbitrary character

Filtering on Columns--projection

Filter on Rows--filter

Row-Record ( tuple ) column--field ( Properties )

1 Select *  fromFruit2 Select *  fromFruitwhereStackinch(3,4,5)3 Select *  fromCarwhereName like  '%5%'--wildcard character% _4 Select *  fromCarwhereName like '% Type'5 Select *  fromCarwhereName like 'PO%'6 Select *  fromCarwhereName like '% Type'7 Select *  fromCarwhereName like '__[3,5]%'--the brackets indicate the choice8 --Sort9 Select *  fromCarOrder  byPrice--AscendingTen Select *  fromCarOrder  byPricedesc  --Descending One Select *  fromCarOrder  byPrice,oilASC, exhaustdesc A Select *  fromCarwherePrice> - Order  by Price - --Statistics of 5 - Select COUNT(*) fromCarwhereName like 'Audi%'--how many records did the Audi start with? the Select AVG(Price) fromCar--statistics car All records the average of price - Select SUM(Price/Oil fromCar - Select *, (Price*0.9) JIU fold fromCar - SelectCode code, name fromCar + Select MAX(Price) fromCar - Select *  fromCarwherePriceinch(Select MIN(Price) fromCar--find the record where the minimum value is located (row) +  A --Grouping at SelectOilCOUNT(*) fromCarGroup  byOilOrder  by COUNT(*) - SelectOilCOUNT(*) fromCarwherePrice> - Group  byOilOrder  by COUNT(*) - SelectBrandMAX(Price) fromCarGroup  byBrand - SelectBrandMin(Price) fromCarGroup  byBrand -  - SelectOilCOUNT(*) fromCarGroup  byOil having COUNT(*)>=2   --having group after filtering in --Group statistics According to social Security numbers; Number of filters greater than 1 - SelectStack fromFruitGroup  byStack having COUNT(*)>1

2014.9.3 database Crud