1. CpSc 3220 The Language of SQL Chapters 4-6

2. Using Functions Function types – Character (string) – Numeric – Date and Time – Summary (aggregate)

3. Some Character Functions concat(str1,str2,…) format(numstr,numDec) insert(str,pos,len,insStr) lcase(str) ucase(str) length(str) substr(str,pos,len)

4. Some Numeric Functions abs(x) acos(x) ceil(x) exp(x) mod(x) pi(x) pow(x,y) round(x,d) truncate(x,d)

5. Some Date/Time Functions curdate() date_format(date,format) datedif(exp1,exp2) dayname(date)

6. Summary Functions count(exp) min(exp) max(exp) sum(exp) avg(exp)

7. Sorting Data SQL uses the ORDER BY clause to sort rows

8. Syntax of the SELECT statement SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [, select_expr...] [FROM table_references [WHERE where_condition] [GROUP BY {col_name | expr | position} [ASC | DESC],... [WITH ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr | position} [ASC | DESC],...] [LIMIT {[offset,] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name(argument_list)] [INTO OUTFILE 'file_name' [CHARACTER SET charset_name] export_options | INTO DUMPFILE 'file_name' | INTO var_name [, var_name]] [FOR UPDATE | LOCK IN SHARE MODE]]

9. Column-Based Logic The select_expr term in the SELECT command can include logical conditions

10. A SELECT with a CASE Expression SELECT column1, column2, caseExpression FROM table

11. A Simple Example SELECT CASE categoryCode WHEN ‘F’ THEN ‘Fruit’ WHEN ‘V’ THEN ‘Vegetable’ ELSE ‘Other’ END AS ‘CategoryName’ FROM products;

12. The Searched Format SELECT CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2... [ELSE default] END

13. A Searched Format Example SELECT CASE WHEN categoryCode = ‘F’ THEN ‘Fruit’ WHEN categoryCode=‘V’ THEN ‘Vegetable’ ELSE ‘Other’ END AS ‘CategoryName’ FROM products;