I only have less than 2,000 Records / 11 Columns (including the Unique ID). This seems to me the simple and fast solution. The more I think at this problem to be solved, the more I think the solution is to create a brand new Table with the Columns I need, then drop the previous one (or better: create a brand new file). The question is How do I edit the sql_master Table ? RecordSet, search the Record that holds the Column to change its name, do it just like any RecordSet,
#SQLITE DROP COLUMN CODE#
If it is possible to rename the now useless Column name (in sql_master), I can change my current code (only add two new Columns and give a new name to the useless COlumn fo fit my needs). Termes de recherche pour accder cette page : add column sql add column add column sql delete column rename column sql drop column. Since now, because it tooks me time to add Columns to the Table, I do not wanted to rename the old table create a new one and populate it with the old contents / delete the “old Tables”. Drop columns from a Table Compose a CREATE TABLE statement with a new table name that uses a SELECT AS clause followed by a list of the columns or field names. In my code, I use the Column Names to access their contents, so from the data base point of view, the order of appearance of the Columns is not a problem for me. I never think I can modify the sql_master contents ! I just fired it and I can see my three added Columns at the end of the previous columns. I build an utility that allow me to load all defined table including sql_master and report their contents. Lastly, the new table is printed using the new name, students.For renaming only columns, you can edit the sqlmaster table. Now that we don’t need the old table, the students table is deleted using the DROP TABLE statement, and the new_students table is renamed students using the ALTER TABLE statement. So it is better way to create a new table with the changes according to your requirement, then drop the original table and again rename the just created new table to the original table name. Additionally, the order of columns in the SELECT statement matters while inserting data from one table to another, and after insertion, the new table is printed. Dropping columns and renaming does not supported by SQLite. Note that except the last_name, everything else is inserted. Next, using the INSERT INTO statement, all the rows from the students table are inserted into new_students. Many sqlite tools do this for you behind the scenes, but in Xojo you have to do all the work yourself. You have to create a copy of the table (along with its data), drop the original table, recreate the original without the column, and copy the data back (minus the column you’re dropping). Note that the schema of the new_students table is different from the students table it does not have the last_name column. SqLite does not support dropping a column. Now, a new table is created, namely, new_students it mimics the new table. then you can drop the old table, rename the new table so that it has the same name as the old one before, and create indexes and other things you need on that table. Next, it inserts some rows into the newly created table using the INSERT INTO statement and then prints the table content. The SQL script above first creates a table, students it tries to mimic the old table. SELECT "Students" SELECT "-" SELECT * FROM students SELECT "" SELECT "New Students" SELECT "-" SELECT * FROM new_students SELECT "" - dropping or deleting the old tableĭROP TABLE students - renaming the new table to the old table's nameĪLTER TABLE new_students RENAME TO students - printing new table INSERT INTO new_students SELECT id, first_name, age FROM students - printing new table
SELECT "Students" SELECT "-" SELECT * FROM students SELECT "" - creating new tableĬREATE TABLE new_students ( id INTEGER PRIMARY KEY, name TEXT NOT NULL, age INT NOT NULL ) - inserting data from an old table into the new table
#SQLITE DROP COLUMN HOW TO#
INSERT INTO students VALUES ( 1, "Stefan", "Salvatore", 13) INSERT INTO students VALUES ( 2, "Damon", "Salvatore", 14) INSERT INTO students VALUES ( 3, "Elena", "Gilbert", 12) INSERT INTO students VALUES ( 4, "Caroline", "Forbes", 12) INSERT INTO students VALUES ( 5, "Bonnie", "Bennett", 13) - printing old table Lets look at an example that shows how to drop a table using the SQLite DROP TABLE statement. CREATE TABLE students ( id INTEGER PRIMARY KEY, first_name TEXT NOT NULL, last_name TEXT NOT NULL, age INT NOT NULL ) - inserting some data into the old table
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