SQL WHERE Statement.

WHERE statement for row selection.

• Just as we choose columns to specify a list of column names from one or more tables, we can select rows with the where statement
• You can use WHERE statement to select columns in several data handling occasions, as with UPDATE, DELETE and not at least SELECT statement.
• It is also possible to connect several tables together with a WHERE statement even though we have a own JOIN statement for this.
• There are several alternative ways to select the table rows:
  1. Selection with Comparison operators (=, <, >, and so on).
  2. Selection with logical AND, OR, NOT.
  3. Selection with BETWEEN, NOT BETWEEN (from and to values).
  4. Selection with IN, NOT IN (list of values).
  5. Selection with LIKE, NOT LIKE (Used by text pattern search).
  6. Selection with IS NULL, IS NOT NULL (none existing, existing).