SQL · Theory

SELECT Record

← All stacks

Theory

35/439

SELECT Record

Asha only reaches for SELECT Record when student names has to stay correct in marks table.

Keep SELECT Record small. Asha should finish student names in a few lines, not a 40-line dump.

Without SELECT Record, marks table gets messy and student names is hard to trust.

Use SELECT Record when student names must stay clear. If a simpler SQL step works, use that instead.

Don’t do this with SELECT Record — SELECT * in production reports. Interviewers spot it in ten seconds.

SELECT Record is not a lonely heading. Asha ties it to student names.

Close SELECT Record with — “If I skip it, student names goes wrong like this: SELECT * in production reports.”

Diagram

  FROM students
        │
        ▼
  WHERE city = 'Pune'
        │
        ▼
  SELECT name, marks

Exam tip

Say SELECT Record in one breath, then SELECT name, marks FROM …, then SELECT * in production reports.

SELECT Record — sample query

CREATE TABLE employees (id INTEGER PRIMARY KEY, name TEXT, dept TEXT, salary INTEGER);
INSERT INTO employees VALUES
  (1, 'Asha', 'Eng', 70000),
  (2, 'Ravi', 'Eng', 65000),
  (3, 'Neha', 'HR', 50000);
SELECT name, salary FROM employees WHERE dept = 'Eng' ORDER BY salary DESC;

SELECT Record — sELECT projects columns; WHERE filters; ORDER BY sorts.

Short notes

DefSELECT Record — Asha uses it for student names in marks table.
RuleSELECT Record → SELECT name, marks FROM ….
RememberSELECT Record + an index (marks table).
UseSELECT Record in marks table (student names).
TrapSELECT Record — SELECT * in production reports.
ExSELECT Record → student names.

CREATE TABLE employees (id INTEGER PRIMARY KEY, name TEXT, dept TEXT, salary INTEGER); INSERT INTO employees VALUES (1, 'Asha', 'Eng', 70000), (2, 'Ravi', 'Eng', 65000), (3, 'Neha', 'HR', 50000); SELECT name, salary FROM employees WHERE dept = 'Eng' ORDER BY salary DESC;

SELECT Record

SELECT Record — sample query

Short notes

Questions

SELECT Record

SELECT Record — sample query

Short notes

Questions