What are CRUD Operations? – Database Management System (DBMS)

🌿 What is CRUD Operations?

CRUD operations are the four basic functions that are considered essential for interacting with any database or persistent storage system. The acronym CRUD stands for:

Operation	SQL Command	Description
Create	`INSERT`	Add new records to the database
Read	`SELECT`	Retrieve data from the databaseUpdate
Update	`UPDATE`	Modify existing data in the database
Delete	`DELETE`	Remove data from the database

<!DOCTYPE html>
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<head>
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Students — CRUD Operations</title>
<style>
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</style>
</head>
<body>

<div class="infographic-crudrunner" id="crudrunner">

  <div class="cr-topbar">
    <button class="cr-showfull-btn" id="crShowFullBtn" type="button">👁️ Show full SQL script</button>
  </div>

  <div class="cr-fullcode-panel" id="crFullCodePanel">
    <div class="cr-fullcode-scroll">
      <div class="cr-fullcode"><span class="cr-cm">-- Create: add the table, then add records</span>
<span class="cr-kw">CREATE TABLE</span> students (
    id <span class="cr-kw">INT AUTO_INCREMENT PRIMARY KEY</span>,
    name <span class="cr-kw">VARCHAR</span>(100) <span class="cr-kw">NOT NULL</span>,
    age <span class="cr-kw">INT</span>,
    grade <span class="cr-kw">VARCHAR</span>(5)
);

<span class="cr-kw">INSERT INTO</span> students (name, age, grade) <span class="cr-kw">VALUES</span>
(<span class="cr-str">'Alice'</span>, <span class="cr-num">18</span>, <span class="cr-str">'A'</span>),
(<span class="cr-str">'Bob'</span>, <span class="cr-num">17</span>, <span class="cr-str">'B'</span>),
(<span class="cr-str">'Charlie'</span>, <span class="cr-num">19</span>, <span class="cr-str">'A+'</span>);

<span class="cr-cm">-- Read: view the data</span>
<span class="cr-kw">SELECT</span> * <span class="cr-kw">FROM</span> students;

<span class="cr-cm">-- Update: change existing data</span>
<span class="cr-kw">UPDATE</span> students
<span class="cr-kw">SET</span> grade = <span class="cr-str">'A+'</span>
<span class="cr-kw">WHERE</span> name = <span class="cr-str">'Bob'</span>;

<span class="cr-cm">-- Delete: remove a record</span>
<span class="cr-kw">DELETE FROM</span> students
<span class="cr-kw">WHERE</span> name = <span class="cr-str">'Bob'</span>;</div>
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  <div class="cr-frame">

    <!-- Step: CREATE -->
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      <div class="cr-step-done-pill" data-step="Create"><span>✓ Create ran</span><span class="chevron">▾ view code</span></div>
      <div class="cr-step-code-full">
        <div class="cr-code-scroll">
          <div class="cr-code"><span class="cr-cm">-- Create: add the table, then add records</span>
<span class="cr-kw">CREATE TABLE</span> students (
    id <span class="cr-kw">INT AUTO_INCREMENT PRIMARY KEY</span>,
    name <span class="cr-kw">VARCHAR</span>(100) <span class="cr-kw">NOT NULL</span>,
    age <span class="cr-kw">INT</span>,
    grade <span class="cr-kw">VARCHAR</span>(5)
);

<span class="cr-kw">INSERT INTO</span> students (name, age, grade) <span class="cr-kw">VALUES</span>
(<span class="cr-str">'Alice'</span>, <span class="cr-num">18</span>, <span class="cr-str">'A'</span>),
(<span class="cr-str">'Bob'</span>, <span class="cr-num">17</span>, <span class="cr-str">'B'</span>),
(<span class="cr-str">'Charlie'</span>, <span class="cr-num">19</span>, <span class="cr-str">'A+'</span>);</div>
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        <div class="cr-run-row">
          <button class="cr-run-btn" id="crCreateBtn" type="button">▶ Run Create</button>
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    <!-- Step: READ -->
    <div class="cr-step" id="stepRead">
      <div class="cr-step-done-pill" data-step="Read"><span>✓ Read ran</span><span class="chevron">▾ view code</span></div>
      <div class="cr-step-code-full">
        <div class="cr-code-scroll">
          <div class="cr-code"><span class="cr-cm">-- Read: view the data</span>
<span class="cr-kw">SELECT</span> * <span class="cr-kw">FROM</span> students;</div>
        </div>
        <div class="cr-run-row">
          <button class="cr-run-btn" id="crReadBtn" type="button">▶ Run Read</button>
        </div>
      </div>
    </div>

    <!-- Step: UPDATE -->
    <div class="cr-step" id="stepUpdate">
      <div class="cr-step-done-pill" data-step="Update"><span>✓ Update ran</span><span class="chevron">▾ view code</span></div>
      <div class="cr-step-code-full">
        <div class="cr-code-scroll">
          <div class="cr-code"><span class="cr-cm">-- Update: change existing data</span>
<span class="cr-kw">UPDATE</span> students
<span class="cr-kw">SET</span> grade = <span class="cr-str">'A+'</span>
<span class="cr-kw">WHERE</span> name = <span class="cr-str">'Bob'</span>;</div>
        </div>
        <div class="cr-run-row">
          <button class="cr-run-btn" id="crUpdateBtn" type="button">▶ Run Update</button>
        </div>
      </div>
    </div>

    <!-- Step: DELETE -->
    <div class="cr-step" id="stepDelete">
      <div class="cr-step-done-pill is-danger-done" data-step="Delete"><span>✓ Delete ran</span><span class="chevron">▾ view code</span></div>
      <div class="cr-step-code-full">
        <div class="cr-code-scroll">
          <div class="cr-code"><span class="cr-cm">-- Delete: remove a record</span>
<span class="cr-kw">DELETE FROM</span> students
<span class="cr-kw">WHERE</span> name = <span class="cr-str">'Bob'</span>;</div>
        </div>
        <div class="cr-run-row">
          <button class="cr-run-btn is-danger" id="crDeleteBtn" type="button">▶ Run Delete</button>
        </div>
      </div>
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    <p class="cr-status" id="crStatus"></p>
    <p class="cr-output-label" id="crOutputLabel">Table: students</p>
    <div class="cr-table-scroll" id="crTableScroll">
      <table class="cr-table" id="crTable">
        <thead><tr><th>id</th><th>name</th><th>age</th><th>grade</th></tr></thead>
        <tbody id="crTableBody"></tbody>
      </table>
    </div>

    <div class="cr-reset-row">
      <button class="cr-run-btn is-secondary" id="crReset" type="button">↺ Reset</button>
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</div>

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})();

(function () {
  const rows = [
    { id: 1, name: 'Alice', age: 18, grade: 'A' },
    { id: 2, name: 'Bob', age: 17, grade: 'B' },
    { id: 3, name: 'Charlie', age: 19, grade: 'A+' }
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  const stepUpdate = document.getElementById('stepUpdate');
  const stepDelete = document.getElementById('stepDelete');

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  const readBtn = document.getElementById('crReadBtn');
  const updateBtn = document.getElementById('crUpdateBtn');
  const deleteBtn = document.getElementById('crDeleteBtn');
  const resetBtn = document.getElementById('crReset');

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    stepEl.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
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  function rowHtml(r) {
    return '<td>' + r.id + '</td><td>' + r.name + '</td><td>' + r.age + '</td><td class="grade-cell">' + r.grade + '</td>';
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    setTimeout(() => {
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      markDone(stepRead);
      revealNext(stepUpdate);
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  updateBtn.addEventListener('click', () => {
    updateBtn.disabled = true;
    updateBtn.textContent = 'Running...';

    const bobRow = tbody.querySelector('tr[data-name="Bob"]');
    bobRow.classList.add('is-updated');

    setTimeout(() => {
      const gradeCell = bobRow.querySelector('.grade-cell');
      gradeCell.textContent = 'A+';
      gradeCell.classList.add('is-changed');
      showStatus('✔️ 1 row updated — Bob\u2019s grade is now A+.', 'good');
      markDone(stepUpdate);
      revealNext(stepDelete);
    }, 500);
  });

  deleteBtn.addEventListener('click', () => {
    deleteBtn.disabled = true;
    deleteBtn.textContent = 'Running...';

    const bobRow = tbody.querySelector('tr[data-name="Bob"]');
    bobRow.classList.remove('is-updated');
    bobRow.classList.add('is-removing');

    setTimeout(() => {
      bobRow.remove();
      showStatus('❌ 1 row deleted — Bob is gone from the table.', 'bad');
      markDone(stepDelete);
    }, 600);
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    outputLabel.classList.remove('is-visible');
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    createBtn.textContent = '▶ Run Create';
    readBtn.disabled = false;
    readBtn.textContent = '▶ Run Read';
    updateBtn.disabled = false;
    updateBtn.textContent = '▶ Run Update';
    deleteBtn.disabled = false;
    deleteBtn.textContent = '▶ Run Delete';
  });
})();
</script>

</body>
</html>

.demo {
  font-family: system-ui, sans-serif;
  padding: 16px;
}

.demo h1 {
  color: #2563eb;
  margin: 0 0 8px;
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.demo p {
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document.querySelector('.demo h1')?.addEventListener('click', () => {
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});

🍀 Why CRUD is Important:

CRUD operations form the foundation of all web and software applications that rely on databases—such as:

Online banking
Social media platforms
E-commerce websites
Library management systems