如何使用 SQL 关键字而不是关键字

Question

I am trying to transform a table of data--I want the rows to become the columns, and the columns to become the rows (like a total complete pivot). I am using the method from this answer to do so.

If it makes any difference, I am running my own SQL server on a Raspberry Pi using PHPMyAdmin.

The table (truncated) looks like this:

Personality|Abby|Aidan|Brandon|Bobby
Agreeabl...|93  |65   |74     |68
Compassion |95  |65   |96     |96
Politeness |81  |9    |21     |12
Conscient..|45  |13   |99     |28

I'm trying to transpose it into this:

Coach  |Agreeableness|Compassion|Politeness|Conscientiousness
Abby   |93           |95        |81        |45
Aidan  |65           |96        |9         |13 
Brandon|74           |96        |21        |99
Bobby  |68           |96        |12        |28

And my query is here:

SELECT Coach,
        MAX(CASE WHEN Personality = 'Agreeableness' THEN value END) `Agreeableness`,
        MAX(CASE WHEN Personality = 'Compassion' THEN value END) `Compassion`,
        MAX(CASE WHEN Personality = 'Politeness' THEN value END) `Politeness`,
        MAX(CASE WHEN Personality = 'Conscientiousness' THEN value END) `Conscientiousness`,
        MAX(CASE WHEN Personality = 'Industriousness' THEN value END) `Industriousness`,
        MAX(CASE WHEN Personality = 'Orderliness' THEN value END) `Orderliness`,
        MAX(CASE WHEN Personality = 'Extraversion' THEN value END) `Extraversion`,
        MAX(CASE WHEN Personality = 'Enthusiasm' THEN value END) `Enthusiasm`,
        MAX(CASE WHEN Personality = 'Assertiveness' THEN value END) `Assertiveness`,
        MAX(CASE WHEN Personality = 'Neuroticism' THEN value END) `Neuroticism`,
        MAX(CASE WHEN Personality = 'Withdrawal' THEN value END) `Withdrawal`,
        MAX(CASE WHEN Personality = 'Volatility' THEN value END) `Volatility`,
        MAX(CASE WHEN Personality = 'Openness' THEN value END) `Openness`,
        MAX(CASE WHEN Personality = 'Intellect' THEN value END) `Intellect`,
        MAX(CASE WHEN Personality = 'Openness (Aspect)' THEN value END) `Openness (Aspect)`
  FROM 
(
  SELECT Personality, Coach,
         CASE Coach
            WHEN 'Abby' THEN Abby
            WHEN 'Aidan' THEN Aidan
            WHEN 'Brandon' THEN Brandon
            WHEN 'Bobby' THEN Bobby
            WHEN 'Carlos' THEN Carlos
            WHEN 'Carrie' THEN Carrie
            WHEN 'Chassidy' THEN Chassidy
            WHEN 'Emily' THEN Emily
            WHEN 'Galen' THEN Galen
            WHEN 'Gavin' THEN Gavin
            **WHEN 'Grant' THEN Grant** #part of interest
            WHEN 'Greg' THEN Greg
            WHEN 'Jack' THEN Jack
            WHEN 'Jenn' THEN Jenn
            WHEN 'Noah' THEN Noah
            WHEN 'Mae' THEN Mae
            WHEN 'Patrick' THEN Patrick
            WHEN 'Titus' THEN Titus
         END value 
    FROM table1 t CROSS JOIN
  (
    SELECT 'Abby' Coach UNION ALL
    SELECT 'Aidan' UNION ALL
    SELECT 'Brandon' UNION ALL 
    SELECT 'Bobby' UNION ALL
    SELECT 'Carlos' UNION ALL
    SELECT 'Carrie' UNION ALL
    SELECT 'Chassidy' UNION ALL
    SELECT 'Emily' UNION ALL
    SELECT 'Galen' UNION ALL
    SELECT 'Gavin' UNION ALL
    SELECT 'Grant' UNION ALL
    SELECT 'Greg' UNION ALL
    SELECT 'Jack' UNION ALL
    SELECT 'Jenn' UNION ALL
    SELECT 'Noah' UNION ALL
    SELECT 'Mae' UNION ALL
    SELECT 'Patrick' UNION ALL
    SELECT 'Titus' UNION ALL
 ) c    
) q 
 GROUP BY Coach
 ORDER BY FIELD(Coach, 'Abby', 'Aidan', 'Brandon', 'Bobby', 'Carlos', 'Carrie', 'Chassidy', 'Emily', 'Galen', 'Gavin', 'Grant', 'Greg', 'Jack', 'Jenn', 'Noah', 'Mae', 'Patrick', 'Titus');

In part of the code I need to write WHEN 'Grant' THEN Grant but that second unquoted Grant becomes a keyword and messes with my code. When I put Grant in single quotes it throws me a syntax error further down where I write ') c' but I suspect my little cheat probably has something to do with it. What shall I do?

Answer 1

You seem to be suggesting that Grant is a column name -- bad choice, but you are stuck with it. The standard way to escape names is to use double quotes:

WHEN 'Grant' THEN "Grant"

Some databases use backticks or square braces instead:

WHEN 'Grant' THEN `Grant`
WHEN 'Grant' THEN [Grant]