presto sql functions

Label: Turn from: http://www.2cto.com/database/201209/154045.html Oracle the REGEXP_SUBSTR function Instructions for using the REGEXP_SUBSTR function in Oracle: The topic is as follows: In Oracle, a statement is implemented to split ' 17,20,23 ' into a collection of ' 17 ', ' 20 ', ' 23 '. The REGEXP_SUBSTR functions are formatted as follows: function regexp_substr (String, pattern, position, occurrence, modifier) __srcstr nbsp : strin

; 7. Rounding The ROUND () function is also used for numerical rounding. SELECT ROUND (56.670) roundValue1, ROUND (56.671) roundValue2, ROUND (-56.670) roundValue3; 8. Find the sine value SELECT SIN (56.67) Sinvalue; 9. Calculate Cosine value SELECT COS (56.67) Cosvalue; 10. To find the sine value of the inverse SELECT 1 / 56.67 , ASIN (1/56.67) Asinvalue; 11. To find the inverse cosine value SELECT 1 / 56.67 , ACOS (1/56.67) Acosvalue; 12. To find the tangent val

Solution for slow SQL query caused by custom functions, function SQL During the report process, one report queries the exchange rate of the corresponding currency, and the exchange rate is in another table, the condition for querying the exchange rate is to query the exchange rate of the previous month of the statistical date in the Exchange Rate Table based on

used when creating views3. SQL ProgrammingFirst, define the variable: DECLARE @ variable name data typeExample: declare @a intVariable assignment: SET @ variable name = valueSet @a=5Select @a--Print directly in the results boxSelect @a=10--Do not output only assign valuesPrint @a--Printing in a message boxExample:DECLARE @price decimal (10,4)Select @price = AVG (price) from carprint ' average price for all cars: ' +cast (@price as varchar (20))Cast f

as follows: Value Abbreviation (SQL Server) Access and ASP Description Year Yy yyyy Year 1753 ~ 9999 Quarter Qq Q Quarter 1 ~ 4 Month Mm M Month 1 ~ 12 Day of the Year Dy Y The number of days in a year, the first day of the year 1-366 Day Dd D Day, 1-31 Weekday Dw W The number of days

1. Case when ... Then ...var from inch context. Products Selectnew { = P.productid, = p. ProductName, 0" Yes " " no " };SELECT [Extent1].[ProductID] as [ProductID], [Extent1].[ProductName] as [ProductName], Case when([Extent1].[UnitsInStock] > 0) ThenN'is a' ELSEN'No' END as [C1] from [dbo].[Product] as [Extent1]LINQ series: LINQ to SQL Transact-

Detach the database as follows:use master go sp_detach_db ‘mydb‘ go Then, copy the data and log files from the current location (D:\Mssql7\Data) to the new location (E:\Sqldata). Reattach the databases that point to the files in the new location as follows:use master go sp_attach_db ‘mydb‘,‘E:\Sqldata\mydbdata.mdf‘,‘E:\Sqldata\mydblog.ldf‘ goUse sp_helpfile to confirm file location changes:use mydb go sp_helpfile go How to move a SQL