db:nrows
Creates an iterator that returns a table of rows from a SELECT - keyed by name
Prototype
db:nrows(sql)Description
Creates an iterator that returns the successive rows selected by the SQL statement given in string sql. Each call to the iterator returns a table in which the named fields correspond to the columns in the database. Here is an example:
db:exec[=[
CREATE TABLE numbers(num1,num2);
INSERT INTO numbers VALUES(1,11);
INSERT INTO numbers VALUES(2,22);
INSERT INTO numbers VALUES(3,33);
]=]
for a in db:nrows('SELECT * FROM numbers') do table.print(a) end
This script prints:
num2: 11
num1: 1
num2: 22
num1: 2
num2: 33
num1: 3
Note: You should let the iterator finish (that is, get to the end of the selected rows) otherwise the database remains locked. So, do not "break" out of the for loop.
db:exec[=[
CREATE TABLE numbers(num1,num2);
INSERT INTO numbers VALUES(1,11);
INSERT INTO numbers VALUES(2,22);
INSERT INTO numbers VALUES(3,33);
]=]
for a in db:nrows('SELECT * FROM numbers') do table.print(a) end
This script prints:
num2: 11
num1: 1
num2: 22
num1: 2
num2: 33
num1: 3
Note: You should let the iterator finish (that is, get to the end of the selected rows) otherwise the database remains locked. So, do not "break" out of the for loop.
Lua functions
- context:aggregate_count - Returns the number of calls to the aggregate step function.
- context:get_aggregate_data - Returns the user-definable data field for callback functions.
- context:result - This function sets the result of a callback function to res.
- context:result_blob - This function sets the result of a callback function to the binary string in blob.
- context:result_error - This function sets the result of a callback function to the error value in err.
- context:result_int - This function sets the result of a callback function to the integer value in number
- context:result_null - This function sets the result of a callback function to nil.
- context:result_number - This function sets the result of a callback function to the value number.
- context:result_text - This function sets the result of a callback function to the string in str.
- context:set_aggregate_data - Set the user-definable data field for callback functions to udata.
- context:user_data - Returns the userdata parameter given in the call to install the callback function.
- db:busy_handler - Sets or removes a busy handler for a database
- db:busy_timeout - Sets a busy handler
- db:changes - Returns number of changes by the most recent SQL statement
- db:close - Closes a database
- db:close_vm - Finalizes all statements that have not been explicitly finalized
- db:create_aggregate - Creates an aggregate callback function
- db:create_collation - Creates a collation callback
- db:create_function - Creates a callback function
- db:errcode - Returns the most recent result code
- db:errmsg - Returns the most recent error message
- db:exec - Executes SQL statements
- db:interrupt - Interrupts any pending operation
- db:isopen - Tests if the database is open
- db:last_insert_rowid - Returns the key of the most recent insert into the database
- db:prepare - Compiles an SQL statement
- db:progress_handler - Installs a progress callback function
- db:rows - Creates an iterator that returns a table of rows from a SELECT - numerically keyed
- db:total_changes - Returns total number of changes
- db:trace - Installs debug trace callback
- db:urows - Creates an iterator that returns the rows from a SELECT
- sqlite3.complete - Checks for a complete SQL statement
- sqlite3.open - Opens or creates a database
- sqlite3.open_memory - Opens a database in memory
- sqlite3.version - Returns the SQLite version
- stmt:bind - Binds a value to a parameter
- stmt:bind_blob - Binds a blob to a parameter
- stmt:bind_names - Binds values in a table to parameters
- stmt:bind_parameter_count - Returns the largest parameter index
- stmt:bind_parameter_name - Returns the name of the n'th paremeter
- stmt:bind_values - Binds values to parameters
- stmt:columns - Returns number of columns in the result set
- stmt:finalize - Frees a prepared statement
- stmt:get_name - Returns the name of a column in a result set
- stmt:get_named_types - Returns a table of names and types for the columns in a result set
- stmt:get_named_values - Returns a table of names and values for the columns in a result set
- stmt:get_names - Returns a table of the names of all columns in a result set
- stmt:get_type - Returns the type of a column in a result set
- stmt:get_types - Returns a table of the types of all columns in a result set
- stmt:get_unames - Returns a list of names of the columns in a result set
- stmt:get_utypes - Returns a list of types of the columns in a result set
- stmt:get_uvalues - Returns a list of values of the columns in a result set
- stmt:get_value - Returns the value of a column in a result set
- stmt:get_values - Returns a table of the values of all columns in a result set
- stmt:isopen - Checks if the statement is open
- stmt:nrows - Creates an iterator that returns a table of rows from a SELECT - keyed by name
- stmt:reset - Resets an SQL statement, so it can be executed again
- stmt:rows - Creates an iterator that returns a table of rows from a SELECT - numerically keyed
- stmt:step - Executes a previously-prepared SQL statement
- stmt:urows - Creates an iterator that returns the rows from a SELECT