📄 que_050.htm
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<title>Ocp test </title>
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<b>QUESTION 050
</b></p><hr color="#99CCFF">
<p>Examine the data in the EMPLOYEES table. <br>
<br>EMPLOYEES<br></p><table border="1" bordercolor="gray">
<span style="font-size:18pt;">
<tr>
<td align="center" bgcolor="#99CCFF">
<p><b>EMPLOYEE_ID</b></p></b>
</td>
<td align="center" bgcolor="#99CCFF">
<p><b>EMP_NAME</b></p></b>
</td>
<td align="center" bgcolor="#99CCFF">
<p><b>DEPT_ID</b></p></b>
</td>
<td align="center" bgcolor="#99CCFF">
<p><b>MGR_ID</b></p></b>
</td>
<td align="center" bgcolor="#99CCFF">
<p><b>JOB_ID</b></p></b>
</td>
<td align="center" bgcolor="#99CCFF">
<p><b>SALARY</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>101</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Smith</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>20</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>120</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>SA_REP</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>4000</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>102</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Martin</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>10</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>105</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>CLERK</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>2500</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>103</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Chris</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>20</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>120</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>IT_ADMIN</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>4200</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>104</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>John</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>30</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>108</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>HR_CLERK</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>2500</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>105</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Diana</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>30</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>108</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>IT_ADMIN</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>5000</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>106</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Smith</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>40</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>110</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>AD.ASST</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>3000</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>108</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Jennifer</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>30</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>110</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>HR_DIR</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>6500</b></p></b>
</td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>110</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Bob</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>40</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b> </b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>EK_DIR</b></p></b>
</td>
<td> <p><b>8000</b></p></td>
</tr>
<tr>
<td align="center" bgcolor="white">
<p><b>120</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>Revi</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>20</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>110</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>SA_DIR</b></p></b>
</td>
<td align="center" bgcolor="white">
<p><b>6500</b></p></b>
</td>
</tr>
</span>
</table>
<p>On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.
Evaluate this DELETE statement:
<br>DELETE employee_id, salary, job_id
<br>FROM employees
<br>WHERE dept_id = 90;
<br>Why does the DELETE statement fail when you execute it? </p><table border="1" bordercolor="gray" width="665">
<form name="youAnsForm">
<span style="font-size:18pt;">
<tr>
<td align="center" width="89">
<p><b><input type="radio" name="AN" value="A"> A.</b></p>
</td>
<td align="left" width="566">
<p> There is no row with dept_id 90 in the EMPLOYEES table.
</p>
</td>
</tr>
<tr>
<td align="center" width="89">
<p><b><input type="radio" name="AN" value="B"> B.</b></p>
</td>
<td align="left" width="566">
<p> You cannot delete the JOB_ID column because it is a NOT NULL column.
</p>
</td>
</tr>
<tr>
<td align="center" width="89">
<p><b><input type="radio" name="AN" value="C"> C.</b></p>
</td>
<td align="left" width="566">
<p> You cannot specify column names in the DELETE clause of the DELETE statement.
</p>
</td>
</tr>
<tr>
<td align="center" width="89">
<p><b><input type="radio" name="AN" value="D"> D.</b></p>
</td>
<td align="left" width="566">
<p> You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.</p>
</td>
</tr>
</span>
</form>
</table>
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