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PART II SQL Development > CHAPTER 9 Updating Data

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he UPDATE statement lets you change data in tables and views by resetting values in one or more columns. A single UPDATE statement can change one, many, or all rows in a table. The new values can come from literal values, variables, or correlated query results. Correlation is the matching of one set of data with another through join operations. This chapter discusses equijoin (equality value joins); Chapter 11 examines join options in detail.

Oracle and MySQL implement basic UPDATE statement syntax in a similar way, but Oracle supports a record update and large object interface that aren’t available in MySQL. The large object interface appends the RETURINING INTO clause to UPDATE statements. MySQL supports a multiple table UPDATE statement, a priority flag, and a LIMIT phrase, which are not supported in Oracle.


  

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