What does SELECT 1 from dual mean?
Re: why does "select 1 from dual" work - what is the "1"? Dual is table that has 1 column and 1 row. 1 is a 'literal' that will be returned by Oracle as it is from the Database. Basically, we use the Dual table to get something/anything from Oracle database once. Lees verder »
What is SELECT 1 from dual?
It has one column, DUMMY, defined to be VARCHAR2(1), and contains one row with a value X. Selecting from the DUAL table is useful for computing a constant expression with the SELECT statement. Because DUAL has only one row, the constant is returned only once. Lees verder »
What does SELECT 1 from mean in SQL?
"SELECT 1 FROM TABLE" is a simple way to check if there are any rows in the specified MySQL table. It doesn't retrieve any data from the table but rather returns a result set with a single column containing the value 1 for each row that satisfies the conditions in the WHERE clause (if any). Lees verder »
What will SELECT * from dual return?
In MySQL, using SELECT * FROM DUAL; will result in an error: "No tables used." This is similar to running SELECT *; without specifying a table. Lees verder »
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