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#MIN Syntax: MIN([DISTINCT] expr) Returns the minimum value of expr. MIN() may take a string argument; in such cases, it returns the minimum string value. See http://dev.mysql.com/doc/refman/5.1/en/mysql-indexes.html. The DISTINCT keyword can be used to find the minimum of the distinct values of expr, however, this produces the same result as omitting DISTINCT. MIN() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html } mysql> SELECT student_name, MIN(test_score), MAX(test_score) -> FROM student -> GROUP BY student_name; >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html , " JOIN y MySQL supports the following JOIN syntaxes for the table_references part of SELECT statements and multiple-table DELETE and UPDATE statements: table_references: table_reference [, table_reference] ... table_reference: table_factor | join_table table_factor: tbl_name [[AS] alias] [index_hint_list] | table_subquery [AS] alias | ( table_references ) | { OJ table_reference LEFT OUTER JOIN table_reference ON conditional_expr } join_table: table_reference [INNER | CROSS] JOIN table_factor [join_condition] | table_reference STRAIGHT_JOIN table_factor | table_reference STRAIGHT_JOIN table_factor ON conditional_expr | table_reference {LEFT|RIGHT} [OUTER] JOIN table_reference join_condition | table_reference NATURAL [{LEFT|RIGHT} [OUTER]] JOIN table_factor join_condition: ON conditional_expr | USING (column_list) index_hint_list: index_hint [, index_hint] ... index_hint: USE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] ([index_list]) | IGNORE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] (index_list) | FORCE {INDEX|KEY} [{FOR {JOIN|ORDER BY|GROUP BY}] (index_list) index_list: index_name [, index_name] ... A table reference is also known as a join expression. The syntax of table_factor is extended in comparison with the SQL Standard. The latter accepts only table_reference, not a list of them inside a pair of parentheses. This is a conservative extension if we consider each comma in a list of table_reference items as equivalent to an inner join. For example: SELECT * FROM t1 LEFT JOIN (t2, t3, t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) is equivalent to: SELECT * FROM t1 LEFT JOIN (t2 CROSS JOIN t3 CROSS JOIN t4) ON (t2.a=t1.a AND t3.b=t1.b AND t4.c=t1.c) In MySQL, CROSS JOIN is a syntactic equivalent to INNER JOIN (they can replace each other). In standard SQL, they are not equivalent. INNER JOIN is used with an ON clause, CROSS JOIN is used otherwise. In general, parentheses can be ignored in join expressions containing only inner join operations. MySQL also supports nested joins (see http://dev.mysql.com/doc/refman/5.1/en/nested-joins.html). Index hints can be specified to affect how the MySQL optimizer makes use of indexes. For more information, see http://dev.mysql.com/doc/refman/5.1/en/index-hints.html. URL: http://dev.mysql.com/doc/refman/5.1/en/join.html r SELECT left_tbl.* FROM left_tbl LEFT JOIN right_tbl ON left_tbl.id = right_tbl.id WHERE right_tbl.id IS NULL; 0http://dev.mysql.com/doc/refman/5.1/en/join.html" HEX$ Syntax: HEX(N_or_S) If N_or_S is a number, returns a string representation of the hexadecimal value of N, where N is a longlong (BIGINT) number. This is equivalent to CONV(N,10,16). If N_or_S is a string, returns a hexadecimal string representation of N_or_S where each character in N_or_S is converted to two hexadecimal digits. The inverse of this operation is performed by the UNHEX() function. URL: http://dev.mysql.com/doc/refman/5.1/en/string-functions.html } mysql> SELECT HEX(255); -> 'FF' mysql> SELECT 0x616263; -> 'abc' mysql> SELECT HEX('abc'); -> 616263 <http://dev.mysql.com/doc/refman/5.1/en/string-functions.html2 REPLACE VSyntax: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [(col_name,...)] {VALUES | VALUE} ({expr | DEFAULT},...),(...),... Or: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name SET col_name={expr | DEFAULT}, ... Or: REPLACE [LOW_PRIORITY | DELAYED] [INTO] tbl_name [(col_name,...)] SELECT ... REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted. See [HELP INSERT]. REPLACE is a MySQL extension to the SQL standard. It either inserts, or deletes and inserts. For another MySQL extension to standard SQL --- that either inserts or updates --- see http://dev.mysql.com/doc/refman/5.1/en/insert-on-duplicate.html. Note that unless the table has a PRIMARY KEY or UNIQUE index, using a REPLACE statement makes no sense. It becomes equivalent to INSERT, because there is no index to be used to determine whether a new row duplicates another. Values for all columns are taken from the values specified in the REPLACE statement. Any missing columns are set to their default values, just as happens for INSERT. You cannot refer to values from the current row and use them in the new row. If you use an assignment such as SET col_name = col_name + 1, the reference to the column name on the right hand side is treated as DEFAULT(col_name), so the assignment is equivalent to SET col_name = DEFAULT(col_name) + 1. To use REPLACE, you must have both the INSERT and DELETE privileges for the table. URL: http://dev.mysql.com/doc/refman/5.1/en/replace.html 3http://dev.mysql.com/doc/refman/5.1/en/replace.html l 2 CONTAINS Contains(g1,g2) Returns 1 or 0 to indicate whether g1 completely contains g2. This tests the opposite relationship as Within(). URL: http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html hhttp://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html " SRID# eSRID(g) Returns an integer indicating the Spatial Reference System ID for the geometry value g. In MySQL, the SRID value is just an integer associated with the geometry value. All calculations are done assuming Euclidean (planar) geometry. URL: http://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions 7mysql> SELECT SRID(GeomFromText('LineString(1 1,2 2)',101)); +-----------------------------------------------+ | SRID(GeomFromText('LineString(1 1,2 2)',101)) | +-----------------------------------------------+ | 101 | +-----------------------------------------------+ khttp://dev.mysql.com/doc/refman/5.1/en/geometry-property-functions.html#general-geometry-property-functions 2 CURRENT_TIMESTAMP Syntax: CURRENT_TIMESTAMP, CURRENT_TIMESTAMP() CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW(). URL: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html Chttp://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html2 SHOW CONTRIBUTORS 0Syntax: SHOW CONTRIBUTORS The SHOW CONTRIBUTORS statement displays information about the people who contribute to MySQL source or to causes that MySQL AB supports. For each contributor, it displays Name, Location, and Comment values. URL: http://dev.mysql.com/doc/refman/5.1/en/show-contributors.html =http://dev.mysql.com/doc/refman/5.1/en/show-contributors.htmly2 VARIANCE (Syntax: VARIANCE(expr) Returns the population standard variance of expr. This is an extension to standard SQL. The standard SQL function VAR_POP() can be used instead. VARIANCE() returns NULL if there were no matching rows. URL: http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html >http://dev.mysql.com/doc/refman/5.1/en/group-by-functions.html 2 DROP SERVER&