Basic and Advance databases programming :: SQL (Structured Query Language) Job Interview Questions and Answers

SQL Interview Questions and Answers will guide us now that SQL (Structured Query Language) is a database computer language designed for managing data in relational database management systems (RDBMS), and originally based upon Relational Algebra. So learn SQL or get preparation for the job of SQL (Structured Query Language) with the help of this SQL Interview Questions with Answers guide

1 What is SQL (Structured Query Language)?
2 What is the SQL*Plus?
3 What is NVL?
4 What is a Character Functions?
5 What is SET?
6 What is a TTITLE & BTITLE?
7 What is sql BREAK?
8 What is sql JOIN?
9 What is sql COMPUTE?
10 What is SQL*Loader?
11 What is sql Consistency?
12 What is sql Set Transaction?
13 What is sql Posting?
14 Explain Order of SQL statement execution?
15 What is sql Synonyms?
16 What is sql Multiple columns?
17 What is sql Minus?
18 What is sql Union?
19 What is sql Transaction?
20 What is sql Locking?
21 What is sql Savepoint?
22 What is sql Commit?
23 What is sql Sequences?
24 What is sql Correlated Subquery?
25 What is sql Intersect?
26 What is SQL Indexes?
27 What are SQL Data types?
28 What is SQL Rollback?
29 What is SQL Mutating Table?
30 Operators used in SELECT statements.
31 The Update Statement:
32 Sort the Rows:
33 BETWEEN ... AND
34 Why does the following command give a compilation error?
35 Which system table contains information on constraints on all the tables created? obtained?
36 State true or false. !=, <>, ^= all denote the same operation?
37 What will be the output of the following query?
38 What is the advantage of specifying WITH GRANT OPTION in the GRANT command?
39 What is the value of comm and sal after executing the following query if the initial value of sal is 10000 UPDATE EMP SET SAL = SAL + 1000, COMM = SAL*0.1;?
40 What command is used to get back the privileges offered by the GRANT command?
41 What is the use of the DROP option in the ALTER TABLE command?
42 What are privileges that can be granted on a table by a user to others?
43 Which is the subset of SQL commands used to manipulate Oracle Database structures, including tables?
44 What command is used to create a table by copying the structure of another table?
45 What is the output of the following query SELECT TRUNC(1234.5678,-2) FROM DUAL;?
46 What is the parameter substitution symbol used with INSERT INTO command?
47 What is difference between TRUNCATE & DELETE?
48 What is SQL sub-query?
49 Explain CONNECT BY PRIOR?
50 Explain UNION, MINUS, UNION ALL and INTERSECT?
51 What is the fastest way of accessing a row in a table?
52 What is referential integrity constraint?
53 What is correlated sub-query?
54 What is SQL ROWID?
55 What is ON DELETE CASCADE?
56 What is difference between CHAR and VARCHAR2? What is the maximum SIZE allowed for each type?
57 What are the pre-requisites to modify datatype of a column and to add a column with NOT NULL constraint?
58 If unique key constraint on DATE column is created, will it validate the rows that are inserted with SYSDATE?
59 How to access the current value and next value from a sequence? Is it possible to access the current value in a session before accessing next value?
60 Can a view be updated/inserted/deleted? If Yes - under what conditions?
61 Which of the following statements is true about implicit cursors?
62 How would the developer define this variable using referential datatypes?
63 If left out, which of the following would cause an infinite loop to occur in a simple loop?
64 The command used to open a CURSOR FOR loop is?
65 Read the following code:
66 For which trigger timing can you reference the NEW and OLD qualifiers?
67 When invoking this procedure, you encounter the error?
68 The CHECK_THEATER trigger of the THEATER table has been disabled. Which command can you issue to enable this trigger?
69 Examine this function:
70 Under which circumstance must you recompile the package body after recompiling the package specification?
71 Which Oracle supplied package can you use to output values and messages from database triggers, stored procedures and functions within SQL*Plus?
72 Which Oracle supplied package will enable this feature?
73 How to implement ISNUMERIC function in SQL *Plus ?
74 What is the difference between Truncate and Delete interms of Referential Integrity?
75 What does the OLTP stands for ?
76 In a client server environment, what would be the major work that the client deals with?
77 What does teh term upsizing refer to?
78 What does the term downsizing refer to?
79 Why do stored procedures reduce network traffic?
80 What is a event handler in sql?
81 What are the various uses of database triggers?
82 Why are the integrity constraints preferred to database triggers?
83 What are the three components of a client server model?
84 What are the disadvantages of the client/server model?
85 What is the first work of Client process?
86 In a Client/Server context, what does API (Application Programming Interface) refer to?
87 What is the main advantage of developing an application using an API?
88 Why is an event driven program referred to a passive program?
89 What is the difference between file server and a database server?
90 What are the two components of ODBC?
91 What is the function of a ODBC Driver?
92 How is a connection established by ODBC?
93 Most important DDL statements in SQL are:
94 SELECT statements:
95 The INSERT INTO Statements:
96 The Delete Statements:
97 What is use of CASCADE CONSTRAINTS?
98 Which system tables contain information on privileges granted and privileges obtained?
99 What is the difference between TRUNCATE and DELETE commands?
100 State true or false. EXISTS, SOME, ANY are operators in SQL?
101 What does the following query do?
102 Which command executes the contents of a specified file?
103 Which command displays the SQL command in the SQL buffer, and then executes it?
104 What will be the output of following query?
105 What operator tests column for absence of data?
106 Which function is used to find the largest integer less than or equal to a specific value?
107 What is the use of DESC in SQL?
108 TRUNCATE TABLE EMP; DELETE FROM EMP; Will the outputs of the above two commands differ?
109 What are the wildcards used for pattern matching.?
110 What is SQL injection?
111 What is a join? Explain the different types of sql joins?
112 Difference between SUBSTR and INSTR?
113 What is an integrity constraint?
114 What is the usage of SAVEPOINTS?
115 What are the data types allowed in a table?
116 How many LONG columns are allowed in a table? Is it possible to use LONG columns in WHERE clause or ORDER BY?
117 Where the integrity constraints are stored in data dictionary?
118 What is CYCLE/NO CYCLE in a Sequence?
119 How will you activate/deactivate integrity constraints?
120 What is a database link?
121 What are the advantages of VIEW?
122 If a view on a single base table is manipulated will the changes be reflected on the base table?
123 Which of the following is not a feature of a cursor FOR loop?
124 Which three of the following are implicit cursor attributes?
125 Which line in the following statement will produce an error?
126 What is the maximum number of handlers processed before the PL/SQL block is exited when an exception occurs?
127 What happens when rows are found using a FETCH statement?
128 Read the following code and explain:
129 Read the following code 2:
130 Read the following code 3?
131 Which procedure can be used to create a customized error message?
132 Examine this database trigger?
133 Procedure and Functions are explicitly executed. This is different from a database trigger. When is a database trigger executed?
134 What occurs if a procedure or function terminates with failure without being handled?
135 Examine this below sql code
136 How to Select last N records from a Table?
137 Which of the Oracle supplied package will enable this feature?
138 What does preemptive in preemptive multitasking mean?
139 What is the most important requirement for OLTP?
140 Why is the most of the processing done at the sever?
141 What does one do when one is rightsizing?
142 What is sql event trigger?
143 What are the types of processes that a server runs?
144 What is an sql integrity constraint?
145 Why is it better to use an integrity constraint to validate data in a table than to use a stored procedure?
146 What are the advantages of client/server model?
147 What are the different topologies available for network?
148 What are the responsibilities of a Server?
149 Give some examples of standard APIs?
150 What is the main disadvantage of developing an application using an API?
151 What are the four types of events?
152 What is sql inheritance?
153 What is the function of a ODBC manager?
154 What description of a data source is required for ODBC?
155 How can variables be passed to a SQL routine?
156 You want to include a carriage return/linefeed in your output from a SQL script, how can you do this?
157 How can you call a PL/SQL procedure from SQL?
158 How do you execute a host operating system command from within SQL?
159 You want to use SQL to build SQL, what is this called and give an example?
160 What SQLPlus command is used to format output from a select?
161 ou want to group the following set of select returns, what can you group on? Max(sum_of_cost), min(sum_of_cost), count(item_no), item_no?
162 What special Oracle feature allows you to specify how the cost based system treats a SQL statement?
163 You want to determine the location of identical rows in a table before attempting to place a unique index on the table, how can this be done?
164 What is a Cartesian product?
165 You are joining a local and a remote table, the network manager complains about the traffic involved, how can you reduce the network traffic?
166 What is the default ordering of an ORDER BY clause in a SELECT statement?
167 What is tkprof and how is it used?
168 What is explain plan and how is it used?
169 How do you set the number of lines on a page of output? The width?
170 How do you prevent output from coming to the screen?
171 How do you prevent Oracle from giving you informational messages during and after a SQL statement execution?
172 How do you generate file output from SQL?