Oracle PL SQL

NULL vs Empty string in oracle

Learn about NULL value and an empty string behavior in oracle database with example queries. NULL means no-value(nothing). An empty string(”) treated as NULL value Let’s create a table suppliers_tbl with the following table definition. Next, we’ll insert following records into this table. The first statement inserts a record with a supplier_name that is null, […]

Pseudo columns in Oracle

Learn about the logical columns that exists in oracle database with example queries. Pseudo columns are nothing but logical columns which behaves like a physical columns in database. Means Pseudo columns behaves like a table columns but is not actually stored in the table. You can select from pseudo-columns, but you cannot insert, update, or […]

Identify columns with NULL values

Learn how to identify the columns present with NULL values in the table with example queries. There can be different ways to identify the columns having NULL values. Below are the few queries to find the NULL value columns in the table. Below is the procedure to find the Columns having all NULL values Below […]

Remove duplicate records using dynamic SQL

Learn how to remove duplicate records present in a table with standard sql queries and also dynamic sql with example queries. For base table reference please click on the given link. To implement removing duplicate rows using dynamic SQL we just want to have the knowledge about Listagg, Execute Immediate concepts. Below are example queries […]

Oracle TIMESTAMP data type

Learn how to use a Time stamp data type ,how to convert a Time stamp in string format to a string Timestamp format using TO_TIMESTAMP string function and TIMESTAMP literal formats. Also Learn how to get the current operating system time stamp and current session DB time stamp with example queries. The Timestamp data type […]

Oracle DATE data type

Learn how to convert a date in string format to a string Date format using TO_DATE function and Date literal formats. Also Learn how to get the current operating system time and current session DB time with example queries. DATE– data type used to store the date(day,month,year) and time(Hours,minutes,seconds) values. Date format of date data […]

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