Why "an INTO clause is expected in this SELECT statement"

SQL Developer is not your database, it's the interface you use to interact with the database. To find your Oracle db version, run

select * from v$version;

To your question: If you want to run a SELECT statement to retrieve information from your tables, just run the SELECT statement directly - don't enclose it within a PL/SQL program unit (an "anonymous block" in your case - the structure with a DECLARE section and BEGIN and END markers).

It seems you want to run a query where you give the start date and the end date as parameters. The way to do that is to include BIND VARIABLES in your query (variable names are preceded by colon : ) You can declare the variables and give them values in a PL/SQL block before running the SELECT query.

Something like this:

SQL> variable start_date varchar2(10)
SQL> begin :start_date := '2021-01-15'; end;
 2 /

PL/SQL procedure successfully completed.


SQL> select to_date(:start_date, 'yyyy-mm-dd') as start_dt from dual;

START_DT
----------
2021-01-15

1 row selected.

Keep in mind the "division of labor" here: VARIABLE is a SQL*Plus command (a command understood by your interface program). The anonymous block where you assign a value to the bind variable is a PL/SQL block (not SQL*Plus interface, but also NOT SQL). Finally, the SELECT statement is a SQL statement. It helps to keep your thoughts organized, to understand which task is performed by which component of your complex setup.

Note that when you declare the variable (with the VARIABLE command) you are not using the colon before the variable name. You do use the colon everywhere else.

Can you adapt this to your example? Give it a try! Note: This is how it works in SQL*Plus; in SQL Developer you can just enter the SELECT statement, with the bind variables; when you execute it, SQL Developer will ask you for values for the bind variable(s). Also, while some systems support the DATE data type for bind variables, others don't; SQL*Plus doesn't, so I used VARCHAR2 and converted to a date in the query itself.

EDIT: I didn't explain the error message. In PL/SQL you can't run standard (SQL) SELECT statements. You can run SELECT statements that return values to PL/SQL variables (either scalar variables or collections, such as arrays of records, etc.) If you have a SELECT statement in a PL/SQL block, you must specify the variable(s) INTO which the values are to be returned. By the look of your code, I assumed you weren't trying to write PL/SQL code that does something, but instead you just wanted to run a SELECT statement that returns results depending on two runtime variables used in the WHERE clause. If I guessed wrong, say so.