課程大綱： Oracle SQL Intermediate - Data Extraction培訓
Limiting results
The WHERE clause
Comparison operators
LIKE Condition
Prerequisite BETWEEN ... AND
IS NULL condition
Condition IN
Boolean operators AND, OR and NOT
Many of the conditions in the WHERE clause
The order of the operators.
DISTINCT clause
SQL functions
The differences between the functions of one and multilines
Features text, numeric, date,
Explicit and implicit conversion
Conversion functions
Nesting functions
Viewing the performance of the functions - dual table
Getting the current date function SYSDATE
Handling of NULL values
Aggregating data using the grouping function
Grouping functions
How grouping functions treat NULL values
Create groups of data - the GROUP BY clause
Grouping multiple columns
Limiting the function result grouping - the HAVING clause
Subqueries
Place subqueries in the SELECT command
Subqueries single and multi-lineage
Operators Subqueries single-line
Features grouping in subquery
Operators Subqueries multi-IN, ALL, ANY
How NULL values ??are treated in subqueries
Operators collective
UNION operator
UNION ALL operator
INTERSECT operator
MINUS operator
Further Usage Of Joins
Revisit Joins
Combining Inner and Outer Joins
Partitioned Outer Joins
Hierarchical Queries
Further Usage Of Sub-Queries
Revisit sub-queries
Use of sub-queries as virtual tables/inline views and columns
Use of the WITH construction
Combining sub-queries and joins
Analytics functions
OVER clause
Partition Clause
Windowing Clause
Rank, Lead, Lag, First, Last functions
Retrieving data from multiple tables (if time at end)
Types of connectors
The use NATURAL JOIN
Aliases tables
Joins in the WHERE clause
INNER JOIN
External Merge LEFT, RIGHT, FULL OUTER JOIN
Cartesian product
Aggregate Functions (if time at end)
Revisit Group By function and Having clause
Group and Rollup
Group and Cube
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