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Access|server| Show | Page Access's Design view has a good feature-----design column annotations, which allows the designer to see clearly the meaning of each column. The general SQL Server does not have this function when building a table, but he has extended properties, this function is also good, you can write the comments here, and then the corresponding resu
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The Design view of access has a good feature-----design column annotations, which allows the designer to see clearly the meaning of each column. The general SQL Server does not have this function when building a table, but he has extended properties, this function is also good, you can write the comments here, and then the corresponding results as RS back to the page to apply
I think it might be useful to d
Tags: Map SQL Server operator arithmetic rules overlap List section allowsPartitioning column RulesThe partitioning column exists on each member table and identifies the available data in a particular table through a CHECK constraint. The partitioning column must adhere to the following rules:Each base table has a partition column that has key values enforced by the CHECK constraint. The key range of the CH
Delete data columnsThe data columns that are built, wrong, or duplicated in the development or production process need to be deleted.Use the SSMS database management tool to delete data column mode one1. Open database--Select data Table-"Expand Data Sheet-" Expand Data Column-"Select the data column to delete-" Right click-"SELECT Delete-" in the Pop-up box click OK.Way Two1. Open Database-"Open data Sheet-" Right click-"SELECT Design.2, in the Design
Label:Let's take a look at the example below: Table tables Field 1 Field 2 ID Name 1 A 2 b 3 C 4 C 5 b The library structure is probably like this, this is just a simple example, the actual situation will be much more complex. For example, if I want to use a single statement to find all the data that name does not repeat, then you must Use distinct to remove redundant duplicate records. The results from the select DISTINCT name from table are: ---------- Name AC It seems to be working, but what
: Table_source Pivot (aggregate function (Value_column) pivot_column for (columnlist)) A little explanation: Table_source: Is the table we want to convert. Pivot_column: Is the column name for row to column. Value_column: Is the value of the column after the conversion. Columnlist is the column to be generated. This is also the case with pivot, which can be used to write the same result: Select Studentname,
[Chinese] Chinese,
[math] math,
[English] 中文版
from
(SELECT * from
Aggregate functions such as SQL max can only perform n-row operations on the same column. If n-column operations are performed, the case statement is generally used for determination. If the number of columns is small, it is easier to write, if there are too many columns, it will be troublesome.
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Tags: compute Ros man Date Judge Special One create MicThe computed column differs from the column that requires us to assign the value manually or by the program, whose value is derived from the computed value of the other columns in the table. For example, if a table contains a quantity column number and a price column, we can create a calculated column amount amount to represent the result value of the quantity * unit price, and after the amount co
Existing table table1, four int field f1,f2,f3,f4, now query to get the maximum value in the four column and only need to return the maximum value
Method One:
Select Case if F12>f34 then F12 else F34 end as Maxnum to
(Select Case when F1>f2 then F1 else F2 end as F12 , case when
F3>f4 then F3 else F4 end as F34 to table1) as T1 ORDER BY maxnum Desc
The effect is as follows:
Method Two:
Select top 1 * "from" (
select F1 as Maxnum, ' F1 ' as ColumnName from TABLE1
UNION
SELECT F2
For SQLSERVER2000 and earlier versions, an auto-incrementing column must be used in combination with a temporary table.
For SQL SERVER 2000 and earlier versions, you must use an auto-incrementing column and a temporary table.
For SQL SERVER 2000 and earlier versions, you must use an auto-incrementing column and a tem
Server
This article mainly summarizes how the identity column is handled in replication
1. Snapshot replication
In snapshot replication, you typically do not need to consider the attributes of an identity column.
2. Transactional replication
Example:
Publish database A, subscribe to database B, publication is t_test_a, subscription table is T_test_b
CREATE TABLE t_test_a
(ID int IDENTITY (1,1),
Name varchar (50)
)
CREATE TABLE T_test_b
(ID int IDENT
temporary table is created by a stored procedure or an application executed by multiple users at the same time, SQL Server must be able to differentiate the tables created by different users. Therefore, SQL Server adds a digital suffix to the table name of each local temporary table internally. The full name of a temp
primary key)Insert into # mytemptable values (1)
If a local temporary table is created by a stored procedure or is executed by multiple users at the same timeProgramSQL Server must be able to differentiate the tables created by different users. Therefore, SQL Server adds a digital suffix to the table name of each local temporary table internally. The full name
The data table contains a column of data, as shown in 1:
Figure 1 data table
Now we need to divide the data in this column into three columns.
The SQL code is as follows:
1,
SelectMax (case when F1 % 3 = 1 then F1 else 0 end),Max (case when F1 % 3 = 2 then F1 else 0 end) B,Max (case when F1 % 3 = 0 then F1 else 0 end) cFrom hlr151Group by (F1-1)/3
Effect:
2,
SelectC1 = A. F1, C2 = B. F1, C3 = C.
SQL Max such aggregate functions can only be for the same column of n row operations, if the N column operations, generally use case statements to judge, if the column is relatively easy to write, the list of more trouble. --------------------------------------------------------------------------------/* Test name: Using XML Find aggregations between arbitrary columns Test functionality: Make min, Max, SU
Tags: and insert ROM info level creat update Set SelectCREATE TRIGGER [dbo]. [Updataalarmlevel]on [dbo]. [Alarm_alarm_info]After inserts, update– after updating and insertingAsBEGINIf update (transfernum) or update (Potentialloss) – event triggered if the Transfernum or Potentialloss two column in the Alarm_alarm_info table changes;declare @transferNum int;DECLARE @potentialLoss decimal (20,2);declare @alarmLeve int;Select @transferNum =transfernum from inserted;--inserted represents the current
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