SQL · Theory

INT

Theory

309/439

INT

INT is a whole number. TINYINT, SMALLINT, MEDIUMINT, BIGINT differ by range. INT UNSIGNED cannot be negative (good for ids). AUTO_INCREMENT is usually INT or BIGINT.

Marks 0–100: INT or TINYINT. Don’t INT(11) as ‘max 11 digits’ — the display width is a leftover, not a limit (deprecated).

Trap — INT for phone. Trap: INT(1) as boolean — use TINYINT(1) by habit, still 0/1.

On the example next to this theory: INT: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Exam tip

roll INT PRIMARY KEY, marks INT

INT — sample query

-- INT
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

INT: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefINT = integer. UNSIGNED = no negatives.
RuleIDs INT/BIGINT. Phone VARCHAR.
TrapINT(11) as a real size limit.

SQL · Theory

INT

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Theory

309/439

INT

INT is a whole number. TINYINT, SMALLINT, MEDIUMINT, BIGINT differ by range. INT UNSIGNED cannot be negative (good for ids). AUTO_INCREMENT is usually INT or BIGINT.

Marks 0–100: INT or TINYINT. Don’t INT(11) as ‘max 11 digits’ — the display width is a leftover, not a limit (deprecated).

Trap — INT for phone. Trap: INT(1) as boolean — use TINYINT(1) by habit, still 0/1.

On the example next to this theory: INT: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Exam tip

roll INT PRIMARY KEY, marks INT

INT — sample query

-- INT
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

INT: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefINT = integer. UNSIGNED = no negatives.
RuleIDs INT/BIGINT. Phone VARCHAR.
TrapINT(11) as a real size limit.

INT

INT — sample query

Short notes

Questions

INT

INT — sample query

Short notes

Questions