Databases and SQL
0 of 26 solved
26 questions
- ACID properties with an exampleTransactionsEasyConceptual
- WHERE vs HAVINGSQL clausesEasyConceptual
- PRIMARY KEY vs UNIQUE constraintsConstraintsEasyConceptual
- The constraint types in PostgreSQLConstraintsEasyConceptual
- DELETE vs TRUNCATE vs DROPDDL and DMLEasyConceptual
- Join types explainedJoinsEasyConceptual
- Second-highest salarySubqueries and aggregatesEasySQL
- Count employees in salary bands with CASECASE expressionsEasySQL
- Monthly order count and revenueDate functionsEasySQL
- Find e-mail addresses registered more than onceGROUP BY and HAVINGEasySQL
- Shortlist students by branch and CGPASELECT, WHERE, ORDER BYEasySQL
- Average CGPA for branches with at least three studentsGROUP BY and HAVINGEasySQL
- Customers who never placed an orderLEFT JOINEasySQL
- Case-insensitive name search with ILIKEPattern matchingEasySQL
- SERIAL vs IDENTITY columnsDDL and DMLMediumConceptual
- What is an index and when does it help?Indexes and performanceMediumConceptual
- Reading EXPLAIN and EXPLAIN ANALYZEIndexes and performanceMediumConceptual
- Transactions and isolation levels in PostgreSQLTransactionsMediumConceptual
- View vs materialized viewViewsMediumConceptual
- Department(s) with the largest total payrollAggregation and subqueriesMediumSQL