Can we use select query within cursor. What exactly are you trying to accomplish? Yes it will work but you will end-up with multiple result-sets. Declare a Table Variable and insert into that table variable and select from the table variable after the loop ends.
What does SELECT statement do to a cursor?
For example, a SELECT statement returns a set of rows which is called a result set. Sometimes the application logic needs to work with one row at a time rather than the entire result set at once. This can be done using cursors.
Why should I not use select * in SQL?
By using SELECT * you can be returning unnecessary data that will just be ignored but fetching that data is not free of cost. This results in some wasteful IO cycles at the DB end, since you will be reading all of that data off the pages, then perhaps you could have read the data from index pages.
Is select * a good practice?
SELECT * returns more data than required to the client, which in turn will use more network bandwidth. This increase in network bandwidth also means that data will take a longer time to reach the client application, which could be SSMS or your Java application server.
What is the * symbol called in SQL?
A wildcard character is used to substitute one or more characters in a string. Wildcard characters are used with the LIKE operator. The LIKE operator is used in a WHERE clause to search for a specified pattern in a column.
Which are the types of cursor *?
There are 2 types of Cursors: Implicit Cursors, and Explicit Cursors.
In which type of cursor we use SELECT into statement?
The implicit cursor SQL and its attributes %NOTFOUND , %FOUND , %ROWCOUNT , and %ISOPEN provide information about the execution of a SELECT INTO statement.
What are the 4 cursor attributes?
Each cursor has a set of attributes that enables an application program to test the state of the cursor. These attributes are %ISOPEN, %FOUND, %NOTFOUND, and %ROWCOUNT. This attribute is used to determine whether a cursor is in the open state.
Why SELECT * is not preferred in embedded SQL programs?
Why SELECT * is not preferred in embedded SQL programs? Program might retrieve the columns which it might not use, leading on I/O over head. The chance of an index only scan is lost.
Is SELECT * slower than SELECT column?
For your question just use SELECT *. If you need all the columns there’s no performance difference.
What does =* mean in SQL?
What does the asterisk (*) symbol mean in SQL?
The asterisk or star symbol ( * ) means all columns. The semi-colon ( ; ) terminates the statement like a period in sentence or question mark in a question.
Which is an SQL*Plus command?
SQL*Plus is a command-line tool that provides access to the Oracle RDBMS. SQL*Plus enables you to: Enter SQL*Plus commands to configure the SQL*Plus environment. Startup and shutdown an Oracle database.
Is select * select all same?
SELECT ALL means ALL rows, i.e including duplicate rows. (The opposite is SELECT DISTINCT , where duplicate rows are removed.) ALL is the default, and most people write just SELECT instead of SELECT ALL . SELECT * means all columns.
Why is an asterisk (*) used here?
It is most commonly used to signal a footnote, but it is sometimes also used to clarify a statement or to censor inappropriate language.
What does * do in a search?
The asterisk is a commonly used wildcard symbol that broadens a search by finding words that start with the same letters. Use it with distinctive word stems to retrieve variations of a term with less typing.
Is mouse pointer a cursor?
In human–computer interaction, a cursor is an indicator used to show the current position on a computer monitor or other display device that will respond to input from a text input or pointing device. The mouse cursor is also called a pointer, owing to its resemblance in usage to a pointing stick.
Is cursor a pointer?
The cursor is a pointer that indicates a link. Typically an image of a pointing hand. The program is busy in the background, but the user can still interact with the interface (in contrast to wait ).
Why are cursors called cursors?
The cursor is so named because it indicates the current position in the result set, just as the cursor on a computer screen indicates current position.
