Datatype of any column can be changed if all rows of the column contain nulls. Size of a character/raw column or the precision of a numeric column can always be increased. Size of a datatype of a column can be reduced as long as the change does not require data to be modified | Bản quyền thuộc COMMIT., JSC. Oracle Database 10g: SQL Fundamentals – Review 1- 1- Bản quyền thuộc COMMIT., JSC. SQL Statements SELECT Data Manipulation Language – DML Transaction Control Language – TCL Data Definition Language – DDL Data Control Language – DCL 1- Level 1 Level 2 Level 3 Syntax SELECT * FROM table WHERE conditions; SELECT Statements Syntax SELECT * | {[DISTINCT] col|expr [[AS] alias], } FROM table | view | subquery [WHERE {condition(s)}] [GROUP BY col,.] [HAVING {condition(s)}] [ORDER BY {col, expr, alias} [ASC|DESC]] 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions Character Functions Case-manipulation Functions LOWER(col|expr) UPPER(col|expr) INITCAP(col|expr) Character-manipulation Functions CONCAT(col1|expr1, col2|expr2) SUBSTR(col|expr, [m], [n]) LENGTH(col|expr) INSTR(col|expr, ‘string’, [m], [n]) LPAD | RPAD (col|expr, n, ‘string’) TRIM(leading|trailing|both ‘char’ FROM ‘source_string’) REPLACE(text, search_str, replacement_str) 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions Number Functions ROUND(col|expr, [n]) TRUNC(col|expr, [n]) MOD(m, n) 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions Date Functions SYSDATE MONTHS_BETWEEN(date1, date2) ADD_MONTHS(date, n) NEXT_DAY(date, ‘char’) LAST_DAY(date) ROUND(date[,’format_model’]) TRUNC(date[,’format_model’]) 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions Conversion Functions Date Character TO_CHAR(date, ‘format_model’) Number Character TO_CHAR(number, ‘format_model’) Character Date TO_DATE(char, ‘format_model’) Character Number TO_NUMBER(char, ‘format_model’) 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions General Functions NVL(expr1, expr2) NVL2(expr1, expr2, expr3) NULLIF(expr1, expr2) COALESCE(expr1, expr2, ., exprn) 1- Bản quyền thuộc COMMIT., JSC. CASE Expression CASE expr WHEN comparison_expr1 THEN return_expr1 [WHEN comparison_expr2 THEN return_expr2 . WHEN comparison_exprn THEN | Bản quyền thuộc COMMIT., JSC. Oracle Database 10g: SQL Fundamentals – Review 1- 1- Bản quyền thuộc COMMIT., JSC. SQL Statements SELECT Data Manipulation Language – DML Transaction Control Language – TCL Data Definition Language – DDL Data Control Language – DCL 1- Level 1 Level 2 Level 3 Syntax SELECT * FROM table WHERE conditions; SELECT Statements Syntax SELECT * | {[DISTINCT] col|expr [[AS] alias], } FROM table | view | subquery [WHERE {condition(s)}] [GROUP BY col,.] [HAVING {condition(s)}] [ORDER BY {col, expr, alias} [ASC|DESC]] 1- Bản quyền thuộc COMMIT., JSC. Single-Row Functions Character Functions Case-manipulation Functions LOWER(col|expr) UPPER(col|expr) INITCAP(col|expr) Character-manipulation Functions CONCAT(col1|expr1, col2|expr2) SUBSTR(col|expr, [m], [n]) LENGTH(col|expr) INSTR(col|expr, ‘string’, [m], [n]) LPAD | RPAD (col|expr, n, ‘string’) TRIM(leading|trailing|both ‘char’ FROM ‘source_string’) REPLACE(text, .
