Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_19266557_1 (original_air_date VARCHAR, _number VARCHAR)

### Question ###
For episode number 7, what was the numbers of original air dates?

### Accurate SQL ###

SELECT COUNT(original_air_date) FROM table_19266557_1 WHERE _number = 7