As an example of good databases we can quote ‘Oracle’, ‘SQL Server’, ‘IBM DB2’, ‘MySQL’, ‘SYBASE’, among others. It is natural that in a niche so defined and with so much expectation of growth there’s a lot of competition, and consequently several (good) options. In the Telecom and IT area for example, numerous elements, alarms, meters and gauges, complaints and service calls, customer data and various other variables need to be stored properly so they can later be processed to extract results as analyses and reports. And in any area where there’s this need for data usage, there will also be a form of storage and control thereof, such as large databases. The trend is that this growth will increase more and more. ON table_lumn_name=table_name2.There’s no doubt the use of data nowadays is much bigger than just a little while ago. HAVING aggregate_function(column_name) operator value SELECT column_name, aggregate_function(column_name) IF EXISTS (SELECT * FROM table_name WHERE id = ?) String Functions: ASCII CHAR_LENGTH CHARACTER_LENGTH CONCAT CONCAT_WS FIELD FIND_IN_SET FORMAT INSERT INSTR LCASE LEFT LENGTH LOCATE LOWER LPAD LTRIM MID POSITION REPEAT REPLACE REVERSE RIGHT RPAD RTRIM SPACE STRCMP SUBSTR SUBSTRING SUBSTRING_INDEX TRIM UCASE UPPER Numeric Functions: ABS ACOS ASIN ATAN ATAN2 AVG CEIL CEILING COS COT COUNT DEGREES DIV EXP FLOOR GREATEST LEAST LN LOG LOG10 LOG2 MAX MIN MOD PI POW POWER RADIANS RAND ROUND SIGN SIN SQRT SUM TAN TRUNCATE Date Functions: ADDDATE ADDTIME CURDATE CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURTIME DATE DATEDIFF DATE_ADD DATE_FORMAT DATE_SUB DAY DAYNAME DAYOFMONTH DAYOFWEEK DAYOFYEAR EXTRACT FROM_DAYS HOUR LAST_DAY LOCALTIME LOCALTIMESTAMP MAKEDATE MAKETIME MICROSECOND MINUTE MONTH MONTHNAME NOW PERIOD_ADD PERIOD_DIFF QUARTER SECOND SEC_TO_TIME STR_TO_DATE SUBDATE SUBTIME SYSDATE TIME TIME_FORMAT TIME_TO_SEC TIMEDIFF TIMESTAMP TO_DAYS WEEK WEEKDAY WEEKOFYEAR YEAR YEARWEEK Advanced Functions: BIN BINARY CASE CAST COALESCE CONNECTION_ID CONV CONVERT CURRENT_USER DATABASE IF IFNULL ISNULL LAST_INSERT_ID NULLIF SESSION_USER SYSTEM_USER USER VERSION SQL Server FunctionsĭROP INDEX table_name.index_name (SQL Server)ĭROP INDEX index_name ON table_name (MS Access)
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