ALTER TABLE statement modifies, adds, drops, or renames table columns. New feature in Oracle 9i Release 2 allows column renaming
CREATE TABLE command creates new database tables. Tables can be created in main, temp or attached databases. Every CREATE TABLE statement must specify table name. Table names starting with "sqlite_" are reserved for internal use
ALTER TABLE modifies table structure including columns, indexes, and storage engine. Requires ALTER, CREATE, and INSERT privileges. Multiple ALTER, ADD, DROP, and CHANGE clauses allowed in single statement
SQL joins combine data from multiple tables into result sets. Tables are arranged horizontally in the FROM clause. Leftmost table is the base table, rightmost table is the joined table
ALTER TABLE modifies existing table definitions. ACCESS EXCLUSIVE lock required unless explicitly specified. Multiple subcommands can be combined for bulk changes
Changing column data type is necessary when existing type is restrictive or broad. Backup is essential before making structure changes in production