BranchesTags

Latest commit

History

5 Commits

Folders and files

NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md

Repository files navigation

HackerRank SQL challenges

Description

My solutions of HackerRank SQL challenges executed on MySQL environment.

Table of Contents

No.Sub Domain
01Basic Select

Basic Select Challenges

No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution

About

Solutions to HackerRank's SQL challenges

Topics

hackerrank-solutionshackerrank-sql-challengesql

Resources

Readme
Activity

Stars

2 stars

Watchers

1 watching

Forks

0 forks
Report repository

Releases

Packages

Contributors

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
BranchesTags
Latest commit
History
5 Commits
Folders and files
NameName
Last commit message
Last commit date
01-Basic-Select
01-Basic-Select
README.md
README.md
Repository files navigation
HackerRank SQL challenges
Description
My solutions of HackerRank SQL challenges executed on MySQL environment.
Table of Contents
No.Sub Domain
01Basic Select
Basic Select Challenges
No.ChallengesSolutions
01Revising the Select Query ISQL Solution
02Revising the Select Query IISQL Solution
03Select AllSQL Solution
04Select By IDSQL Solution
05Japanese Cities' AttributesSQL Solution
06Japanese Cities' NamesSQL Solution
07Weather Observation Station 1SQL Solution
08Weather Observation Station 3SQL Solution
09Weather Observation Station 4SQL Solution
10Weather Observation Station 5SQL Solution
11Weather Observation Station 6SQL Solution
12Weather Observation Station 7SQL Solution
13Weather Observation Station 8SQL Solution
14Weather Observation Station 9SQL Solution
15Weather Observation Station 10SQL Solution
16Weather Observation Station 11SQL Solution
17Weather Observation Station 12SQL Solution
18Higher Than 75 MarksSQL Solution
19Employee NamesSQL Solution
20Employee SalariesSQL Solution
About
Solutions to HackerRank's SQL challenges
Topics
hackerrank-solutionshackerrank-sql-challengesql
Resources
Readme
Activity
Stars
2 stars
Watchers
1 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors