I've created a table inside a database, with a column called 'recipeName'. After committing the newly created table to the database, it comes up with this error:
OperationalError: table recipes has no column named recipeName
Here's the code for creating the table, and for entering the stuff into the database...
cursor.execute("""CREATE TABLE IF NOT EXISTS \
recipes('id INT PRIMARY KEY AUTO_INCREMENT, recipeName')""")
#Save data to database
conn.commit()
cursor.execute("""INSERT INTO recipes(recipeName) VALUES('%s')""" % (recipeName))
I'll be really appreciative of any help I get... this is confusing me quite a lot... I've been working it for days now, and I haven't been able to find a fix...
Thanks in advance :)
Ryan :)
cursor.execute("CREATE TABLE IF NOT EXISTS recipes([id] INTEGER PRIMARY KEY AUTOINCREMENT, [recipeName])")
you only had one column named : 'id INT PRIMARY KEY AUTO_INCREMENT, recipeName'
also in sqlite you need to use INTEGER PRIMARY KEY AUTOINCREMENT (not INT and AUTO_INCREMENT)
Related
This is the relation I want to create for my quiz app and im using python
Module:
c.execute("""CREATE TABLE Questions (
mod_id INTEGER PRIMARY KEY,
mod_name TEXT NOT NULL
)""")
Question:
c.execute("""CREATE TABLE Questions (
quest_id INTEGER PRIMARY KEY,
quest_name TEXT NOT NULL,
mod_id INTEGER NOT NULL,
FOREIGN KEY (mod_id)
REFERENCES Modules (mod_id)
)""")
Now Since the each feedback correspont to 1 question, how do i sort of create one to one relationship? should I do the same as I did for the question table? would this be handle automatically by sqlite3??
Appreciate all sort of help Thanks!!!
EDIT: Does my feedback table need to have a primary key?? I think no because when accesing the feeback table to delete or add data we just pass the question ID as the parameter to look that row up.
I am creating a database from different CSV files. After doing this I have tried to define the primary key table by table but I got an error.
c.execute("ALTER TABLE patient_data ADD PRIMARY KEY (ID);").fetchall()
OperationalError: near "PRIMARY": syntax error
Maybe the best thing to avoid this error is to define the primary key when the table is create but I dont know how to do that. I have been working with python for a few years but today is my first approach with SQL.
This is the code I use to import a CSV to a table
c.execute('''DROP TABLE IF EXISTS patient_data''')
c.execute(''' CREATE TABLE patient_data (ID, NHS_Number,Full_Name,Gender, Birthdate, Ethnicity, Postcode)''')
patients_admitted.to_sql('patient_data', conn, if_exists='append', index = False)
c.execute('''SELECT * FROM patient_data''').fetchall()
This is too long for a comment.
If your table does not have data, just re-create it with the primary key definition.
If your table does have data, you cannot add a primary key in one statement. Why not? The default value is either NULL or constant. And neither is allowed as a primary key.
And finally, SQLite does not allow you to add a primary key to an existing table. The solution is to copy the data to another table, recreate the table with the structure you want, and then copy the data back in.
I am trying to create a database using python to execute the SQL commands (for CS50x problem set 7).
I have created a table with an id field set to AUTO_INCREMENT, but the field in the database is populated only by NULL values. I just want it to have an incrementing id starting at 1.
I've tried searching online to see if I'm using the right syntax and can't find anything obvious, nor can I find someone else with a similar problem, so any help would be much appreciated.
Here is the SQL command I am running:
# For creating the table
db.execute("""
CREATE TABLE students (
id INTEGER AUTO_INCREMENT PRIMARY KEY,
first_name VARCHAR(255) NOT NULL,
middle_name VARCHAR(255) DEFAULT (NULL),
last_name VARCHAR(255) NOT NULL,
house VARCHAR(10),
birth INTEGER
);
""")
# An example insert statement
db.execute("""
INSERT INTO students (
first_name,
middle_name,
last_name,
house,
birth
)
VALUES (
?, ?, ?, ?, ?
);
""", "Harry", "James", "Potter", "Gryffindor", 1980)
Here is a screenshot of the database schema shown in phpliteadmin :
And here is a screenshot of the resulting database:
My guess is that you are using SQLite with phpliteadmin and not MySql, in which case this:
id INTEGER AUTO_INCREMENT PRIMARY KEY
is not the correct definition of the auto increment primary key.
In fact, the data type of this column is set to INTEGER AUTO_INCREMENT, as you can see in phpliteadmin, which according to 3.1. Determination Of Column Affinity, has INTEGER affinity.
Nevertheless it is the PRIMARY KEY of the table but this allows NULL values.
The correct syntax to have an integer primary key is this:
id INTEGER PRIMARY KEY AUTOINCREMENT
This cannot happen, if your statements are executed correctly.
I notice that you are not checking for errors in your code. You should be doing that!
My guess is that the table is already created without the auto_increment attribute. The create table is generating an error and you are inserting into the older version.
You can fix this by dropping the table before you create it. You should also modify the code to check for errors.
I am trying to add an 'id' primary key column to an already existing MySQL table using alembic. I tried the following...
op.add_column('mytable', sa.Column('id', sa.Integer(), nullable=False))
op.alter_column('mytable', 'id', autoincrement=True, existing_type=sa.Integer(), existing_server_default=False, existing_nullable=False)
but got the following error
sqlalchemy.exc.OperationalError: (OperationalError) (1075, 'Incorrect table definition; there can be only one auto column and it must be defined as a key') 'ALTER TABLE mytable CHANGE id id INTEGER NOT NULL AUTO_INCREMENT' ()
looks like the sql statement generated by alembic did not add PRIMARY KEY at the end of the alter statement. Could I have missed some settings?
Thanks in advance!
I spent some time digging through the alembic source code, and this doesn't seem to be supported. You can specify primary keys when creating a table, but not when adding columns. In fact, it specifically checks and won't let you (link to source):
# from alembic.operations.toimpl.add_column, line 132
for constraint in t.constraints:
if not isinstance(constraint, sa_schema.PrimaryKeyConstraint):
operations.impl.add_constraint(constraint)
I looked around, and adding a primary key to an existing table may result in unspecified behavior - primary keys aren't supposed to be null, so your engine may or may not create primary keys for existing rows. See this SO discussion for more info: Insert auto increment primary key to existing table
I'd just run the alter query directly, and create primary keys if you need to.
op.execute("ALTER TABLE mytable ADD id INT PRIMARY KEY AUTO_INCREMENT;")
If you really need cross-engine compatibility, the big hammer would be to (1) create a new table identical to the old one with a primary key, (2) migrate all your data, (3)delete the old table and (4) rename the new table.
Hope that helps.
You have to remove the primary key that is in the table and then create a new one that includes all columns that you want as the primary key.
eg. In psql use \d <table name> to define the schema, then check the primary key constraint.
Indexes:
"enrollments_pkey" PRIMARY KEY, btree (se_crs_id, se_std_id)
then use this information in alembic
def upgrade():
# ### commands auto generated by Alembic - please adjust! ###
op.add_column('enrollments', sa.Column(
'se_semester', sa.String(length=30), nullable=False))
op.drop_constraint('enrollments_pkey', 'enrollments', type_='primary')
op.create_primary_key('enrollments_pkey', 'enrollments', [
'se_std_id', 'se_crs_id', 'se_semester'])
The results after running \d enrollments should be updated to
Indexes:
"enrollments_pkey" PRIMARY KEY, btree (se_std_id, se_crs_id, se_semester)
This solution worked fine for me.
I am using sqlite with python 2.5. I get a sqlite error with the syntax below. I looked around and saw AUTOINCREMENT on this page http://www.sqlite.org/syntaxdiagrams.html#column-constraint but that did not work either. Without AUTO_INCREMENT my table can be created.
An error occurred: near "AUTO_INCREMENT": syntax error
CREATE TABLE fileInfo
(
fileId int NOT NULL AUTO_INCREMENT,
name varchar(255),
status int NOT NULL,
PRIMARY KEY (fileId)
);
This is addressed in the SQLite FAQ. Question #1.
Which states:
How do I create an AUTOINCREMENT
field?
Short answer: A column declared
INTEGER PRIMARY KEY will
autoincrement.
Here is the long answer: If you
declare a column of a table to be
INTEGER PRIMARY KEY, then whenever you
insert a NULL into that column of the
table, the NULL is automatically
converted into an integer which is one
greater than the largest value of that
column over all other rows in the
table, or 1 if the table is empty. (If
the largest possible integer key,
9223372036854775807, then an unused
key value is chosen at random.) For
example, suppose you have a table like
this:
CREATE TABLE t1( a INTEGER PRIMARY
KEY, b INTEGER ); With this table,
the statement
INSERT INTO t1 VALUES(NULL,123); is
logically equivalent to saying:
INSERT INTO t1 VALUES((SELECT max(a)
FROM t1)+1,123); There is a function
named sqlite3_last_insert_rowid()
which will return the integer key for
the most recent insert operation.
Note that the integer key is one
greater than the largest key that was
in the table just prior to the insert.
The new key will be unique over all
keys currently in the table, but it
might overlap with keys that have been
previously deleted from the table. To
create keys that are unique over the
lifetime of the table, add the
AUTOINCREMENT keyword to the INTEGER
PRIMARY KEY declaration. Then the key
chosen will be one more than than the
largest key that has ever existed in
that table. If the largest possible
key has previously existed in that
table, then the INSERT will fail with
an SQLITE_FULL error code.
It looks like AUTO_INCREMENT should be AUTOINCREMENT see http://www.sqlite.org/syntaxdiagrams.html#column-constraint
You could try
CREATE TABLE fileInfo
(
fileid INTEGER PRIMARY KEY AUTOINCREMENT,
name STRING,
status INTEGER NOT NULL
);
We just changed the order from
NOT NULL, AUTO_INCREMENT
to
AUTO_INCREMENT NOT NULL,
an example :
cursor.execute("CREATE TABLE users(\
user_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,\
user_name VARCHAR(100) NOT NULL)")