Database glossary: Apprentice level
52 Database terms at the Apprentice level, each with a short definition and a link to its full page.
Updated
- Aggregate Function
- A function that summarizes a set of rows into one value.
- ALTER TABLE
- A statement that changes the definition of an existing table.
- Approximate Numeric Type
- A floating-point numeric type that may store an approximation of a value.
- AVG
- An aggregate function returning the average of non-NULL numeric values.
- BETWEEN Predicate
- A predicate testing whether a value falls within an inclusive lower and upper bound.
- CASE Expression
- An expression that chooses a result by evaluating conditions in order.
- Character String Type
- A SQL type whose values are sequences of characters.
- COUNT
- An aggregate function returning the number of qualifying rows or non-NULL expression values.
- CREATE TABLE
- A statement that defines a new table, its columns, and its constraints.
- CREATE VIEW
- A statement that defines a view from a query.
- CROSS JOIN
- A join returning every possible pairing of rows from two table expressions.
- Data Control Language (DCL)
- SQL statements that control database privileges and access.
- Data Definition Language (DDL)
- SQL statements that define or change database structures.
- Data Manipulation Language (DML)
- SQL statements that retrieve or change stored rows.
- Date and Time Type
- A SQL type representing a date, time, timestamp, or interval.
- DELETE
- A statement that removes selected rows from a table.
- DROP TABLE
- A statement that removes a table definition and its stored data.
- Exact Numeric Type
- A numeric type representing values with defined precision and scale without binary approximation.
- EXCEPT
- A set operation returning distinct rows in the first result but not the second.
- EXISTS Predicate
- A predicate that is true when its subquery returns at least one row.
- FETCH FIRST
- A standard clause limiting a query result to its first specified number of rows.
- FULL OUTER JOIN
- A join returning matched rows plus unmatched rows from both sides.
- GROUP BY
- A clause collecting rows with equal grouping values so each group produces one result row.
- HAVING
- A clause filtering groups after grouping and aggregation.
- IN Predicate
- A predicate testing whether a value equals any value in a list or subquery result.
- INNER JOIN
- A join returning only row combinations that satisfy its join condition.
- INSERT
- A statement that adds new rows to a table.
- INTERSECT
- A set operation returning distinct rows present in both query results.
- IS NULL Predicate
- A predicate testing whether a value is NULL.
- JOIN
- A query operation combining related rows from two table expressions.
- Join Condition
- The predicate deciding which rows from joined sources match.
- LEFT OUTER JOIN
- A join returning every left row and matching right rows, using NULLs when no right match exists.
- LIKE Predicate
- A predicate comparing text with a pattern containing wildcard characters.
- MAX
- An aggregate function returning the highest non-NULL value.
- MIN
- An aggregate function returning the lowest non-NULL value.
- OFFSET Clause
- A clause skipping a specified number of ordered result rows.
- ON Clause
- A join clause containing its match condition.
- RIGHT OUTER JOIN
- A join returning every right row and matching left rows, using NULLs when no left match exists.
- Scalar Subquery
- A subquery required to return one column and no more than one row.
- Self Join
- A query that joins a table to another reference to the same table.
- SET Clause
- The UPDATE clause assigning new values to columns.
- Set Operation
- An operation combining compatible query results according to set rules.
- Subquery
- A query nested inside another SQL statement.
- SUM
- An aggregate function adding the non-NULL numeric values in a group.
- Table Subquery
- A subquery producing rows and columns that another query can use as a table.
- Transaction Control Language (TCL)
- SQL statements that complete, reverse, or mark points within transactions.
- UNION
- A set operation combining compatible query results and removing duplicate rows.
- UNION ALL
- A set operation combining compatible query results while retaining duplicate rows.
- UPDATE
- A statement that changes values in existing rows.
- VALUES Clause
- A clause that supplies rows of literal or calculated values.
- View
- A named query whose result can be used much like a table.
- Wildcard Character
- A pattern character representing unknown text, such as % or _ with LIKE.