I would avoid using SELECT *. Specify columns you actually want even though it may be all of them. SQL Server 2005+ SELECT col1, col2 FROM ( SELECT col1, col2, ROW_NUMBER() OVER (ORDER BY ID) AS RowNum FROM MyTable ) AS MyDerivedTable WHERE MyDerivedTable.RowNum BETWEEN @startRow AND @endRow SQL Server 2000 Efficiently Paging Through Large … Read more
Does db/sql batch large datasets on reading into memory ? Is it configurable? [duplicate]
You could try using the Lead() and Lag() SQL Analytic function for this SELECT * from (SELECT *, LAG(AMOUNT) over (partition by user_id order by datetime) as Yesterday_AMOUNT from SALES s ) x where cast(s.datetime as date) = cast(getdaate() as date) and x.AMOUNT <> s.Yesterday_AMOUNT;
The following UPDATE statement will guarantee that each row has a unique MY_TIMESTAMP value, by increasing the milliseconds by the rownum value. EDIT: After Alessandro Rossi pointed out that there could be duplicate values, the following query has been modified to use SYSTIMESTAMP for the update. UPDATE ITEM_HISTORY SET my_timestamp = SYSTIMESTAMP + NUMTODSINTERVAL(rownum/1000, ‘SECOND’); … Read more
Backticks are to be used for table and column identifiers, but are only necessary when the identifier is a MySQL reserved keyword, or when the identifier contains whitespace characters or characters beyond a limited set (see below) It is often recommended to avoid using reserved keywords as column or table identifiers when possible, avoiding the … Read more
The correct way to avoid SQL injection attacks, no matter which database you use, is to separate the data from SQL, so that data stays data and will never be interpreted as commands by the SQL parser. It is possible to create an SQL statement with correctly formatted data parts, but if you don’t fully … Read more