Editing Troubleshooting of PostgreSQL

Troubleshooting of [https://www.postgresql.org/ PostgreSQL]

== How to fix Syntax error of PostgreSQL ==
=== How to fix Syntax error: 7 ERROR:  LIMIT #,# syntax is not supported ===
Query syntax mer error
<pre>
SELECT * 
FROM my_table
LIMIT 0,10
</pre>

Error message
<pre>
Uncaught PDOException: SQLSTATE[42601]: Syntax error: 7 ERROR:  LIMIT #,# syntax is not supported                                                         
HINT:  Use separate LIMIT and OFFSET clauses.
</pre>

Correct query syntax<ref>[http://www.sqlines.com/postgresql/limit_offset PostgreSQL Queries - OFFSET and LIMIT - Guide, Examples and Alternatives - SQLines Tools]</ref>
<pre>
SELECT * 
FROM my_table
LIMIT 10 OFFSET 0
</pre>

=== How to fix ERROR:  operator does not exist: ` character varying ===
The following SQL query has a syntax error:
<pre>
SELECT `my_columm`
from my_table
LIMIT 10
</pre>

Error message
<pre>
ERROR:  operator does not exist: ` character varying
LINE 1: SELECT `content_hash`
               ^
HINT:  No operator matches the given name and argument type. You might need to add an explicit type cast.
</pre>

To fix the error, update the query with the correct syntax:
<pre>
SELECT my_columm
from my_table
LIMIT 10
</pre>

=== How to fix ERROR: argument of WHERE must be type boolean, not type integer ===
Query syntax mer error
<pre>
SELECT * 
FROM my_table
WHERE 1
</pre>

Correct query syntax
<pre>
SELECT * 
FROM my_table
WHERE 1 = 1
</pre>

or
<pre>
SELECT * 
FROM my_table
WHERE TRUE
</pre>

=== How to fix the ERROR: column "count" does not exist ===
The following SQL query has a syntax error:
<pre>
SELECT count(*) count, content_hash
from my_table
GROUP BY content_hash
having count >= 2
</pre>

To fix the error, update the query with the correct syntax:
<pre>
SELECT count(*) count, content_hash
from my_table
GROUP BY content_hash
having count(*) >= 2
</pre>

=== How to fix: The numeric column data all became null after imported ===
[[Troubleshooting of Navicat for PostgreSQL]]

== Further reading ==
* [https://stackoverflow.com/questions/242822/why-would-someone-use-where-1-1-and-conditions-in-a-sql-clause dynamic sql - Why would someone use WHERE 1=1 AND <conditions> in a SQL clause? - Stack Overflow]
* [https://koalatea.io/postgres-insert-ignore/ Working with Insert Into Ignore in Postgres]

== References ==
<references />



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[[Category:PostgreSQL]]
[[Category:Database]]
[[Category:Data Science]]