// only selects 1 of each
SELECT DISTINCT

// change datatype of column
ALTER TABLE table MODIFY COLUMN table, datatype

// change name of column
ALTER TABLE table RENME COLUMN column_old, column_new

// update multiple values
UPDATE table SET column = column * 1000 WHERE statement

// insert values
INSERT INTO table VALUES (calue1, value2, ...)
INSERT INTO table (column1, column2, ...) VALUES (value1, value2, ...)

// add column
ALTER TABLE table ADD column, datatype {AFTER another_column}

// search by letter
SELECT * FROM table_name WHERE column_name LIKE '%a%'       // contais a
SELECT * FROM table_name WHERE column_name LIKE 'a%';       // starts with a
SELECT * FROM table_name WHERE column_name LIKE '%a';       // ends with a
SELECT * FROM table_name WHERE column_name LIKE '%a_%';     // contains a followed by a single character