I am getting a BadSQLGrammarException, but I cannot see where the error is in the following SQL statement:
insert into comment(comment_date, name, comment) values '4/27/2013', 'Frank', 'Test';
Here is the description of my table. (Yes, I am converting a date into a String. There are probably better ways to do it with SQL, but that's not the question here.)
+--------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| comment_date | varchar(10) | YES | | NULL | |
| name | varchar(200) | YES | | NULL | |
| comment | varchar(200) | YES | | NULL | |
+--------------+--------------+------+-----+---------+-------+
INSERT INTO table (fieldlist) VALUES (valueslist)
^-- ^--
you forgot the indicated brackets.
Try using parentheses around the values, like this:
insert into comment(comment_date, name, comment) values ('4/27/2013', 'Frank', 'Test');
Related
I have SQL for example
show tables from mydb;
It shows the list of table
|table1|
|table2|
|table3|
Then,I use sql sentence for each table.
such as "show full columns from table1 ;"
+----------+--------+-----------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+----------+--------+-----------+------+-----+---------+----------------+---------------------------------+---------+
| id | bigint | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | |
| user_id | bigint | NULL | NO | MUL | NULL | | select,insert,update,references | |
| group_id | int | NULL | NO | MUL | NULL | | select,insert,update,references | |
+----------+--------+-----------+------+-----+---------+----------------+---------------------------------+---------+
So in this case I can use programming language such as .(this is not correct code just showing the flow)
tables = "show tables from mydb;"
for t in tables:
cmd.execute("show full columns from {t} ;")
However is it possible to do this in sql only?
If you are using MySQL you can use the system view - INFORMATION_SCHEMA.
It contains table name and column name (and other details). No loop is require and you can easily filter by other information, too.
SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
If you are using Microsoft SQL Server, you can use the above command
when I ran desc features
+-------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(128) | YES | UNI | NULL | |
+-------+--------------+------+-----+---------+----------------+
I have table like below,
+-----------+----------------------------------------------------------+
| id | name |
+-----------+----------------------------------------------------------+
| 105314659 | latitude |
| 105314658 | final |
+-----------+----------------------------------------------------------+
I ran INSERT INTO features (name) VALUES ('test'), it didnot give auto-increment primary key, like
+-----------+----------------------------------------------------------+
| id | name |
+-----------+----------------------------------------------------------+
| 109728684 | test |
| 105314659 | latitude |
| 105314658 | final |
+-----------+----------------------------------------------------------+
+-----------+----------------------------------------------------------+
| id | name |
+-----------+----------------------------------------------------------+
| 109728690 | test5 |
| 109728688 | test4 |
| 109728687 | test3 |
| 109728686 | test2 |
| 109728684 | test |
| 105314659 | latitude |
| 105314658 | final |
+-----------+----------------------------------------------------------+
anyone has any thoughts ? Thanks !
*** This table I constant delete and insert BTW. But when I ran single insert, it didnot auto incremental id ***
This issue is from
INSERT INTO nlp_request_feature_types (name) VALUES ('test4'); ,
It will cause exc.IntegrityError, like
ERROR 1062 (23000): Duplicate entry 'test4' for key 'features.ix_features', BUT the id = 109728689 , will be allocated.
So when next run INSERT INTO nlp_request_feature_types (name) VALUES ('test5'); , it will be successfully saved into table, and the primary key id = 109728690.
As such, it will give us the illusion that auto-incremental primary key doesnot work. However, it does work, just because our mistake of ERROR 1062 consumed one id.
I have a database like this:
+-------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| PosScore | float | YES | | NULL | |
| NegScore | float | YES | | NULL | |
| SynsetTerms | varchar(45) | YES | | NULL | |
+-------------+-------------+------+-----+---------+----------------+
some of the SynsetTerms have # at the end.
Can I just use an SQL query and remove them?
Thanks in advance.
You can use an update statement:
update t
set SynsetTerms = left(SynsetTerms, length(SynsetTerms) - 1)
where SynsetTerms like '%#';
If you want to remove all occurrences of '#':
update t
set SynsetTerms = replace(SynsetTerms, '#', '')
where SynsetTerms like '%#%';
In your select or update statement just do this:
SELECT replace(synsetTerms, '#','') from table
or
UPDATE table set synsetTerms = replace(synsetTerms, '#','')
if you just want to update the records that contain the '#' symbol you can add the following WHERE clause:
WHERE synsetTerms like '%#'
I was wondering if there's a drawback (other than bad practice) to using something like this
SELECT * FROM my_table WHERE id LIKE '1';
where id is an integer. I know you're supposed to use id=1 but I am writing a java program and if everything can use LIKE it'll be a lot easier for me. Also, so far, everything works fine; I get the correct query results, so if there is no drawback I will continue doing it like this.
edit: I am using MySQL.
MySQL will allow it, but will ignore the index:
mysql> describe METADATA_44;
+---------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+--------------+------+-----+---------+-------+
| AtextId | int(11) | NO | PRI | NULL | |
| num | varchar(128) | YES | | NULL | |
| title | varchar(128) | YES | | NULL | |
| file | varchar(128) | YES | | NULL | |
| context | varchar(128) | YES | | NULL | |
| source | varchar(128) | YES | | NULL | |
+---------+--------------+------+-----+---------+-------+
6 rows in set (0.00 sec)
mysql> explain select * from METADATA_44 where Atextid like '7';
+----+-------------+-------------+------+---------------+------+---------+------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------------+------+---------------+------+---------+------+------+-------------+
| 1 | SIMPLE | METADATA_44 | ALL | PRIMARY | NULL | NULL | NULL | 591 | Using where |
+----+-------------+-------------+------+---------------+------+---------+------+------+-------------+
mysql> explain select * from METADATA_44 where Atextid=7;
+----+-------------+-------------+-------+---------------+---------+---------+-------+------+-------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------------+-------+---------------+---------+---------+-------+------+-------+
| 1 | SIMPLE | METADATA_44 | const | PRIMARY | PRIMARY | 4 | const | 1 | |
+----+-------------+-------------+-------+---------------+---------+---------+-------+------+-------+
1 row in set (0.00 sec)
You'd need to look at the Query Execution Plan on your RDBMS to verify that LIKE with no wildcards is treated as efficiently as an = would be. A quick test in SQL Server shows that it would give you an index scan rather than a seek so I guess it doesn't look at that when generating the plan and for SQL Server using = would be much more efficient. I don't have a MySQL install to test against.
Edit: Just to update this SQL Server seems to handle it fine and do a seek when the data type is varchar. When it is run against an int column though you get the scan. This is because it does an implicit conversion to varchar on the int column so can't use the index.
You are better off writing your query as
SELECT * FROM my_table WHERE id = 1;
otherwise mysql will have to typecast '1' to int which is the type of the column id
so obviously there is a small performance penalty, when u know the type of the column supply the value according to that type
Speed. [15-char filler as there's not much more to say]
Without using any wildcards with LIKE, is should be fine for your needs if the speed/efficiency is something you don't bother with.
A table is:
mysql> desc gifts;
+---------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+----------------+
| giftID | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(80) | YES | | NULL | |
| filename | varchar(80) | YES | | NULL | |
| effectiveTime | datetime | YES | | NULL | |
+---------------+-------------+------+-----+---------+----------------+
the following is ok:
mysql> insert into gifts
-> values (10, "heart", "heart_shape.jpg", now());
Query OK, 1 row affected (0.05 sec)
but is there a way to not specify the "10"... and just let each one be 11, 12, 13... ?
I can do it using
mysql> insert into gifts (name, filename, effectiveTime)
-> values ("coffee", "coffee123.jpg", now());
Query OK, 1 row affected (0.00 sec)
but the column names need to be all specified. Is there a way that they don't have to be specified and the auto increment of primary key still works? thanks.
values (NULL, "heart", "heart_shape.jpg", now());