SQLite Explain
Before the SQLite statement, you can use the "EXPLAIN" keyword or the "EXPLAIN QUERY PLAN" phrase to describe the details of the table.
If the EXPLAIN keyword or phrase is omitted, any modification will cause the query behavior of the SQLite statement and return information about how the SQLite statement operates.
Output from EXPLAIN and EXPLAIN QUERY PLAN is for interactive analysis and troubleshooting only.
The details of the output format may vary between SQLite versions.
Applications should not use EXPLAIN or EXPLAIN QUERY PLAN because their exact behavior is variable and only partially logged.
EXPLAIN The syntax is as follows:
EXPLAIN [SQLite Query]# The syntax of ##EXPLAIN QUERY PLAN
is as follows: EXPLAIN QUERY PLAN [SQLite Query]
Example
Suppose the COMPANY table has the following records:
ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0
Now, let us check the # in the SELECT statement ##Explain
Usage:sqlite> EXPLAIN SELECT * FROM COMPANY WHERE Salary >= 20000;This will produce the following result:
addr opcode p1 p2 p3 ---------- ---------- ---------- ---------- ---------- 0 Goto 0 19 1 Integer 0 0 2 OpenRead 0 8 3 SetNumColu 0 5 4 Rewind 0 17 5 Column 0 4 6 RealAffini 0 0 7 Integer 20000 0 8 Lt 357 16 collseq(BI 9 Rowid 0 0 10 Column 0 1 11 Column 0 2 12 Column 0 3 13 Column 0 4 14 RealAffini 0 0 15 Callback 5 0 16 Next 0 5 17 Close 0 0 18 Halt 0 0 19 Transactio 0 0 20 VerifyCook 0 38 21 Goto 0 1 22 Noop 0 0Now, let us check the
Explain Query Plan
in the SELECT statement. Usage:SQLite> EXPLAIN QUERY PLAN SELECT * FROM COMPANY WHERE Salary >= 20000;rrree
