The GROUP BY statement is used in conjunction with the aggregate functions like SUM to provide means of grouping the result by certain table column or columns.
NVL function is used to substitute a value when a null value is encountered.This is useful in PL/SQL programming where we can supply default values when there is a chance of getting null at run time or to provide useful logging messages.
The oracle SUBSTR functions return a portion of string, beginning at a specified position in the string.This functions allows to extract a substring from a string.To know the position of a string in a string you can use INSTR function.
The oracle INSTR function returns the location of a sub string in a string.The search is case sensitive.If the specified string is not found, then the instr Oracle function will return 0.
This error occurs due to an arithmetic, numeric, string, conversion problem.
This normally displayed as ORA-06502: PL/SQL: numeric or value error:This error can happen because of different scenarios.
This is a Back trace error message.This normally displayed as ORA-06512: at line (linenumber).The below give example is a typical scenario.
The error ORA-12154: TNS:could not resolve the connect identifier specified occurs when the listener could not resolve SERVICE_NAME specified in the connect descriptor.The common causes of this error explained below.
Oracle provide a lot of mechanisms to handle the time and date types.Formatting the date and time objects can be done in different ways.Please read the following articles to know more about timestamp in milliseconds and Date format.
To_timestamp method in oracle is used with string (varchar2 or similar) or character sequences to convert it into timestamp type.The function requires the input string of timestamp and the format string as parameters.
DATE datatype.DATE datatype has the ability to store the month, day, year, century, hours, minutes, and seconds.But TIMESTAMP datatype which stores all the information that the DATE datatype stores,and also includes fractional seconds.