Otherwise, the query plan will be displayed in a tabular format: Statement Testing If the statement fails, you'll get an error message similar to the following: In Navicat's database administration and development tools, you can run the EXPLAIN command with the click of a button. In most relational DBs the query plan command is "explain" or "describe", as in: How the DB is planning to execute the query, e.g.Whether there are any syntax errors in the query if so the query plan command itself will fail.
One way to validate your syntax is to ask your database (DB) for the query plan. The next step is to ascertain whether or not it produces the result that you intended. The first is to verify that the statement is syntactically valid, I.E. The process of testing your statements can be split into two stages. We'll be taking a look at both options in this blog. There are also some solutions that enjoy widespread support.
So what are some options to accurately predict what the result of an INSERT, UPDATE, or DELETE statement will be on production data before running it? Well, that depends on the database vendor and product, at least in part. You can always execute your Data Manipulation Language (DML) statements on a development or test database, but due to differences in the data, this approach makes determining the statement's effects on the production data a craps shoot at best. Other times, a botched UPDATE can cause more harm than the initial issue. In some cases, running a well crafted UPDATE statement in production can save the day. How to Test Insert and Update Statements before Executing Them by Robert Gravelle
0 kommentar(er)
