One of the more interesting aggregation functions is RANK. After doing a standard SELECT and GROUP BY; you can then have SQL rank the results using an aggregated value from another column.
Let’s dive in and look at how RANK works and what can it do for us.
Previous to Oracle 12c limit the number of rows returned usually meant encapsulating the query as a subquery. It wasn’t particularly nice looking and was out of alignment with other relational database query languages.
MySQL uses the LIMIT operator and Microsoft T-SQL uses the TOP operator. In Oracle 12c, Oracle introduced the FETCH FIRST operator. Let’s see how it works.
There are times when we need not just the total value for the column, but subtotal values depending on different column values. Oracle supports subtotal operators through the three key operators they are CUBE, ROLLUP, and GROUPING SETS. Below are examples of each one and how best to use them.
Oracle 12 uses normal SQL statements when doing aggregation. The standard rules for aggregating in SQL apply. You need to group by all non aggregated columns and having clause will be evaluated after the group by operator.
Some examples of aggregation in Oracle PL/SQL are below.
Below are some examples of how to create tables in Oracle 12. PL/SQL, for the most part PL/SQL follows standard SQL conventions.
Below are some examples of how to create tables in Oracle 12. PL/SQL. For the most part PL/SQL follows standard SQL conventions. I will show how to create some tables and some of the more popular options when creating tables.
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