types of cursor in sql server

. No_log and truncate_only are synonymous. Here's a question, what is the activity log, Microsoft's explanation is: The portion of the log file from the first log record that must exist to ensure that the database is successfully rolled back to the last written log record is called the active part of the log, which is the activity log. This is the section of the log required for full database recovery. You can never truncate any part of the activity log. DBCC shrinkdatabase shrinks al

of digits that can be stored (left and right of the decimal point). P must be a value between 1 and 38. The default is 18. The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value between 0 and P. The default is 0. 5-17 bytessmallmoney The currency data between -214,748.3648 and 214,748.3647. 4 bytesMoney data between -922,337,203,685,477.5808 and 922,337,203,685,477.5807. 8 bytesfloat (n) floating precision digital data from -1.79e + 30

Create function fun_a () #标题函数, create function Fun_name () returns OUTPUT_TYPE as begin return value end;returns intAsBeginreturn 1;EndGoCreate function Fun_b () #多语句用户定义函数, create function Fun_name () returns @value table (Colum_list) as begin return; end Returns @tb table (ID int, Name nvarchar (8))AsBeginInsert into @tb (id,name) VALUES (1, ' 111 '), (2, ' 222 ');ReturnEndGoCreate function Fun_c () #内联用户定义函数, create function Fun_name () returns table as return select ...;Returns tableAsRe

right table does not have a matching row in the left table, a null value will be returned for left table.3) Full join or full OUTER joina full outer join returns all rows from the left and right tables. When a row does not have a matching row in another table, the selection list column for the other table contains a null value. If there are matching rows between the tables, the entire result set row contains the data values of the base table. 3. Cross JoinA cross join returns all the rows in t

allowed per column.3, check the constraintsThe check constraint sets the check condition for values in the input column or the entire table, and can limit the input values to ensure the integrity of the database. The check constraint determines the valid value through the logical expression of the data. For example, to define an age ages field, you can limit the range of values inside the age field to between 0 and 150 by creating a check constraint (>=0 and age Only one check constrai

result depends on the setting of the query statement and the query conditions.Statement format for opening a cursor:Exec SQL OPEN If the open cursor is INSENSITIVE, a temporary table is generated when the cursor is opened, and the defined cursor data set is copied from its base table.In

1. Cursor Concept A swimming cursor is a handle or pointer to a context area. When you perform a crud operation in a pl/sql block, Oracle assigns the context area to it in memory. Using the database language to describe a cursor is a position entity that maps on a row of data in the context area result set. A user c

A major reason for using cursor is to convert the set operation into a single record processing method. After retrieving data from a database using SQL, the results are stored in a memory area, and the results are often a collection containing multiple records. The cursor mechanism allows you to access these records row by row in

The cursor mentioned here is of course the transaction-SQL cursor. Any type of cursor will reduce the performance of SQL Server. However, the reason why the cursor exists is that it is

The PL/SQL cursor allows the program to select multiple rows of data from the database, and then separately process each row of data, it provides Oracle with a method to indicate and control each stage of SQL processing. I think you have some knowledge about PL/SQL. Through this article, you will learn: Creation of

1. What is the cursor? Oracle uses two types of cursor: explicit cursor and implicit cursor. No matter how many records are returned by the statement, PL/SQL implicitly declares a cursor