{"id":16153,"date":"2024-04-15T04:56:49","date_gmt":"2024-04-15T04:56:49","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=16153"},"modified":"2024-04-15T04:56:49","modified_gmt":"2024-04-15T04:56:49","slug":"referential-integrity-means-a-do-not-enter-a-value-in-the-foreign-key-field-of-a-child-table-if-that-value-does-not-exist-in-the-primary-key-of-the-parent-table-b-do-not-enter-a-value-in-the-primary","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/referential-integrity-means-a-do-not-enter-a-value-in-the-foreign-key-field-of-a-child-table-if-that-value-does-not-exist-in-the-primary-key-of-the-parent-table-b-do-not-enter-a-value-in-the-primary\/","title":{"rendered":"Referential integrity means A. Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table B. Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table C. Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table D. All of above"},"content":{"rendered":"<p>\r\n    <!-- Check if it's an AMP page -->\r\n            <!-- Non-AMP version -->\r\n        <div class=\"mcq-container\" data-quiz-id=\"quizState_6a98a6b3c6e0b\">\r\n                                            <div class=\"option\" data-option-key=\"option1\" data-is-correct=\"false\">\r\n                    Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option2\" data-is-correct=\"false\">\r\n                    Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option3\" data-is-correct=\"false\">\r\n                    Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option4\" data-is-correct=\"true\">\r\n                    All of above                <\/div>\r\n                            \r\n            <!-- Feedback messages for non-AMP -->\r\n            <div class=\"feedback\" data-feedback=\"wrong\">Answer is Right!<\/div>\r\n            <div class=\"feedback\" data-feedback=\"right\">Answer is Wrong!<\/div>\r\n        <\/div>\r\n\r\n        <script>\r\n        document.addEventListener('DOMContentLoaded', function () {\r\n            var containers = document.querySelectorAll('.mcq-container');\r\n\r\n            containers.forEach(function(container) {\r\n                var options = container.querySelectorAll('.option');\r\n                var feedbackSelect = container.querySelector('[data-feedback=\"select\"]');\r\n                var feedbackWrong = container.querySelector('[data-feedback=\"wrong\"]');\r\n                var feedbackRight = container.querySelector('[data-feedback=\"right\"]');\r\n\r\n                options.forEach(function(option) {\r\n                    option.addEventListener('click', function() {\r\n                        var selectedOption = option.getAttribute('data-option-key');\r\n                        var isCorrect = option.getAttribute('data-is-correct') === 'true';\r\n\r\n                        \/\/ Remove previous selections\r\n                        options.forEach(function(opt) {\r\n                            opt.classList.remove('correct', 'incorrect');\r\n                        });\r\n\r\n                        \/\/ Add the correct\/incorrect class\r\n                        if (isCorrect) {\r\n                            option.classList.add('correct');\r\n                            feedbackRight.hidden = false;\r\n                            feedbackWrong.hidden = true;\r\n                        } else {\r\n                            option.classList.add('incorrect');\r\n                            feedbackRight.hidden = true;\r\n                            feedbackWrong.hidden = false;\r\n                        }\r\n\r\n                        \/\/ Hide select feedback\r\n                        feedbackSelect.hidden = true;\r\n                    });\r\n                });\r\n            });\r\n        });\r\n        <\/script>\r\n    \r\n    <!--more--><\/p>\n<p>The correct answer is D. All of above.<\/p>\n<p>Referential integrity is a database constraint that ensures that the data in one table is consistent with the data in another table. It is implemented by creating a foreign key in the child table that references the primary key of the parent table. This prevents you from entering a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table. It also prevents you from entering a value in the primary key field of child table if that value does not exist in the primary key of the parent table.<\/p>\n<p>For example, let&#8217;s say you have a table called <code>Customers<\/code> with a primary key of <code>CustomerID<\/code>. You also have a table called <code>Orders<\/code> with a foreign key of <code>CustomerID<\/code> that references the <code>CustomerID<\/code> column in the <code>Customers<\/code> table. This means that you can only enter a value in the <code>CustomerID<\/code> <div class=\"youtube-subscribe-container\">\r\n        <a href=\"https:\/\/www.youtube.com\/channel\/UCNHT8lW-JmLC68rjBfZhdkg?sub_confirmation=1\" target=\"_blank\" class=\"youtube-subscribe-button\">\r\n            <span class=\"youtube-icon\">\r\n                <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 576 512\">\r\n                    <path d=\"M549.7 124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z\"\/>\r\n                <\/svg>\r\n            <\/span>\r\n            Subscribe on YouTube\r\n        <\/a>\r\n    <\/div> field of the <code>Orders<\/code> table if that value exists in the <code>CustomerID<\/code> field of the <code>Customers<\/code> table.<\/p>\n<p>Referential integrity is important because it helps to ensure the accuracy and consistency of your data. If you were able to enter a value in the foreign key field of a child table that did not exist in the primary key of the parent table, you would end up with <div class=\"telegram-channel-container\">\r\n        <a href=\"https:\/\/t.me\/pscnotes2025\" target=\"_blank\" class=\"telegram-channel-button\">\r\n            <span class=\"telegram-icon\">\r\n                <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 496 512\">\r\n                    <path fill=\"white\" d=\"M248,8C111,8,0,119,0,256s111,248,248,248s248-111,248-248S385,8,248,8z M362,177L320,367c-3,14-10,18-20,14l-56-41l-27,26 c-3,3-5,5-10,5l4-63L323,196c5-5-1-7-8-3l-98,62l-42-13c-9-3-10-9,2-14l162-63C351,160,365,164,362,177z\"\/>\r\n                <\/svg>\r\n            <\/span>\r\n            Join Our Telegram Channel\r\n        <\/a>\r\n    <\/div> orphaned data. This is data that is no longer related to any other data in the database. Orphaned data can be difficult to manage and can lead to errors.<\/p>\n<p>Referential integrity is also important for performance. When you create a foreign key constraint, the database engine will automatically enforce that constraint. This means that the database engine will not allow you to enter data that violates the constraint. This can help to improve the performance of your database by preventing the database engine from having to search for data that does not exist.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Join Our Telegram Channel Subscribe on YouTube<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[672],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v22.2 (Yoast SEO v23.3) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Referential integrity means A. Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table B. Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table C. Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table D. All of above<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/referential-integrity-means-a-do-not-enter-a-value-in-the-foreign-key-field-of-a-child-table-if-that-value-does-not-exist-in-the-primary-key-of-the-parent-table-b-do-not-enter-a-value-in-the-primary\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Referential integrity means A. Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table B. Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table C. Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table D. 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Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table B. Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table C. Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table D. All of above","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/referential-integrity-means-a-do-not-enter-a-value-in-the-foreign-key-field-of-a-child-table-if-that-value-does-not-exist-in-the-primary-key-of-the-parent-table-b-do-not-enter-a-value-in-the-primary\/","og_locale":"en_US","og_type":"article","og_title":"Referential integrity means A. 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Do not enter a value in the foreign key field of a child table if that value does not exist in the primary key of the parent table B. Do not enter a value in the primary key field of child table if that value does not exist in the primary key of the parent table C. Do not enter a value in the foreign key field of a parent table if that value does not exist in the primary key of the child table D. 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