1. _______ value is used to represent unknown or undefined values.   ZERO   Blank   NULL   Hint Half-n-half Clue   2. Which one of the following operators allow us to concatenate two strings?   +   ||   &   &&   Half-n-half Clue   3. The data type of a column is declared as CHAR(5). Can the column contain a string of four characters?   Yes   No   4. Which of the following symbolic constant yields the current date?   NOW   TODAY   PRESENT_DATE   CURRENT_DATE   Half-n-half Clue   5. What is the POSITION function used for?   To extract the row number of a particular record.   None of the above   To extract the starting position of a string in another string.   Half-n-half Clue   6. SQL is a _______ language.   non-procedural   object-oriented   procedural   Half-n-half Clue   7. The data type used to store variable length bit strings is _______.   BIT(length)   BIT VARYING(length)   VARBIT2(length)   VARBIT(length)   Half-n-half Clue