[Sql: actual] number of functions used sql summary

1、CAST

CAST: Format Conversion Functions

用法：CAST (expression AS data_type)

expression The : Any valid SQServer expression.

AS : for separating two parameters, before the data to be processed it is AS, AS after the data type is to be converted.

data_type : data type provided by the target system, including the sql_variant and bigint, can not use the user-defined data types.

Applications: The time to convert  VARCHAR  type

 The CAST (f.order_created_time the AS  VARCHAR ) the AS  ' Order Time ' ,

 

 2、CONCAT

1, Function: connecting a plurality of strings into a single string.

Syntax: concat (str1, str2, ...)

Applications: urban Address Province spliced ​​into a complete delivery address

CONCAT(f.receiver_province_name,',',f.receiver_city_name,',',f.receiver_district_name,',',f.receiver_address) AS '收货地址',

 

3、GROUP_CONCAT

1, Function: the value of the same group by a packet generated in the connect, the result returns a string.

Applications: There may be a variety of the same order of payment, the balance of payments have to send another micro-channel payment, and therefore the time of connection to use GROUP_CONCAT

   The GROUP_CONCAT (
         the CASE 
            the WHEN op.pay_type =  . 1  THEN  ' payment of balance ' 
            the WHEN op.pay_type =  2  THEN  ' micro-channel pay ' 
            the WHEN op.pay_type =  . 3  THEN  ' Alipay ' 
            the WHEN op.pay_type =  . 4  THEN  ' bank card payment ' 
            the WHEN OP .pay_type =  5  THEN  ' cash payment ' 
            the WHEN op.pay_type =  6  THEN  ' offer full deduction '
            The WHEN op.pay_type =  . 7  THEN  ' online payment ' 
        the END )

 

4、ROUND

Function: ROUND function for the numeric field rounded to the specified decimal

Application: The price of the class to be accurate to the decimal point

ROUND( ( f.pay_amount + f.discount_amount ) / f.sku_quantity / 100,