Prev Next

@(@\newcommand{\B}[1]{ {\bf #1} } \newcommand{\R}[1]{ {\rm #1} } \newcommand{\W}[1]{ \; #1 \; }@)@This is dismod_at-20221105 documentation: Here is a link to its current documentation .
Modify a Column of an Sqlite Database

Deprecated
Syntax
     As Program
     As Python Function
See Also
Warning
arg_list
database
table_name
column_name
row_expression
value_expression
Expressions
statements
Log Table
Example

Deprecated
This command was deprecated on 2021-12-05.

Syntax

As Program
dismodat.py database modify 
 table_name column_name row_expression value_expression 
 statement_one statement_two ...
As Python Function
dismod_at.modify_command(database, arg_list)

See Also
It is simpler to use the set_command when it is it is capable of making a change.

Warning
You can change any value in the database using the modify command. It is suggested that you re-run the init_command , unless you are certain that the set of model_variables was not affected by this change.

arg_list
This is a list of strings containing the arguments in the program syntax. To be specific, arg_list[0] is table_name , arg_list[1] is column_name , e.t.c.

database
Is the file name corresponding to the Sqlite database.

table_name
Is the name of the table in the database that is modified.

column_name
Is the name of the column in the table that is modified.

row_expression
This is a python expression that evaluates to True or False. Only rows where the expression is True are modified.

value_expression
This is a python expression that specifies the value to be placed in the specified column when the row expression is True.

Expressions
For each row, an expression can reference the value in a column using the corresponding column name. In other words, for each column, a variable with the column name is set to the value in that column.

statements
There may be zero or more python statements at the end of the command line. Each one is executed before the expressions are evaluated. For example, one of the statements might be 
 
 from math import exp
This would make the function exp(x) available for use in row_expression and value_expression .

Log Table
See dismodat.py .

Example
The file modify_command.py contains an example and test using this command.
Input File: python/dismod_at/modify_command.py