90 lines
4.0 KiB
Markdown
90 lines
4.0 KiB
Markdown
---
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title: SQL LIKE Operator
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localeTitle: SQL LIKE运算符
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---
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## SQL LIKE运算符
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### LIKE运营商定义
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`LIKE`运算符用于`WHERE`或`HAVING` （作为`GROUP BY`一部分），以便在列中包含特定字符模式时将所选行限制为项。
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### 本指南将演示：
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* 确定字符串是否以给定的字符串模式开始或结束
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* 确定字符串中间是否存在模式
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* 确定字符串中是否包含字符串
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### 列以给定的字符串模式开始或结束
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此SQL将选择`FullName`以“Monique”开头或以“Greene”结尾的学生。
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```sql
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SELECT studentID, FullName, sat_score, rcd_updated
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FROM student
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WHERE
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FullName LIKE 'Monique%' OR -- note the % at the end but not the beginning
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FullName LIKE '%Greene'; -- note the % at the beginning but not the end
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```
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```text
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+-----------+---------------+-----------+---------------------+
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| studentID | FullName | sat_score | rcd_updated |
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+-----------+---------------+-----------+---------------------+
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| 1 | Monique Davis | 400 | 2017-08-16 15:34:50 |
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| 5 | Alvin Greene | 1200 | 2017-08-16 15:34:50 |
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+-----------+---------------+-----------+---------------------+
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2 rows in set (0.00 sec)
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```
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### 字符串模式位于列的中间
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此SQL将选择名称中包含“ree”的学生。
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```sql
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SELECT studentID, FullName, sat_score, rcd_updated
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FROM student
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WHERE FullName LIKE '%ree%'; -- note the % at the beginning AND at the end
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```
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```text
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+-----------+----------------+-----------+---------------------+
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| studentID | FullName | sat_score | rcd_updated |
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+-----------+----------------+-----------+---------------------+
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| 5 | Alvin Greene | 1200 | 2017-08-16 15:34:50 |
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| 6 | Sophie Freeman | 1200 | 2017-08-16 15:34:50 |
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+-----------+----------------+-----------+---------------------+
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2 rows in set (0.00 sec)
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```
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### 字符串不在列中
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您可以在LIKE之前放置“NOT”以使用字符串模式排除行而不是选择它们。 此SQL排除FullName列中包含“cer Pau”和“Ted”的记录。
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```sql
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SELECT studentID, FullName, sat_score, rcd_updated
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FROM student
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WHERE FullName NOT LIKE '%cer Pau%' AND FullName NOT LIKE '%"Ted"%';
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```
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```text
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+-----------+----------------------+-----------+---------------------+
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| studentID | FullName | sat_score | rcd_updated |
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+-----------+----------------------+-----------+---------------------+
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| 1 | Monique Davis | 400 | 2017-08-16 15:34:50 |
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| 2 | Teri Gutierrez | 800 | 2017-08-16 15:34:50 |
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| 4 | Louis Ramsey | 1200 | 2017-08-16 15:34:50 |
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| 5 | Alvin Greene | 1200 | 2017-08-16 15:34:50 |
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| 6 | Sophie Freeman | 1200 | 2017-08-16 15:34:50 |
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| 8 | Donald D. Chamberlin | 2400 | 2017-08-16 15:35:33 |
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| 9 | Raymond F. Boyce | 2400 | 2017-08-16 15:35:33 |
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+-----------+----------------------+-----------+---------------------+
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7 rows in set (0.00 sec)
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```
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_以下是与上面的where子句结果集进行比较的当前完整学生列表。_
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```sql
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SELECT studentID, FullName, sat_score, rcd_updated FROM student;
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```
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\`\`\`文本 + ----------- + ------------------------ + ----------- + --------------------- + | studentID | FullName |坐_得分| rcd_更新了| + ----------- + ------------------------ + ----------- + --------------------- + | 1 |莫妮克戴维斯| 400 | 2017-08-16 15:34:50 | | 2 | Teri Gutierrez | 800 | 2017-08-16 15:34:50 | | 3 | Spencer Pautier | 1000 | 2017-08-16 15:34:50 | | 4 |路易斯拉姆齐| 1200 | 2017-08-16 15:34:50 | | 5 | Alvin Greene | 1200 | 2017-08-16 15:34:50 | | 6 |索菲弗里曼| 1200 | 2017-08-16 15:34:50 | | 7 |埃德加弗兰克“特德”科德| 2400 | 2017-08-16 15:35:33 | | 8 |唐纳德D. Chamberlin | 2400 | 2017-08-16 15:35:33 | | 9 |雷蒙德F.博伊斯| 2400 | 2017-08-16 15:35:33 | + ----------- + ------------------------ + ----------- + --------------------- + 9行（0.00秒） |