filter_by_string

GPUdb.filter_by_string( table_name = None, view_name = '', expression = None,
                        mode = None, column_names = None, options = {} )

Calculates which objects from a table, collection, or view match a string expression for the given string columns. The 'mode' may be:

• search

  : full text search query with wildcards and boolean operators, e.g. '(bob* OR sue) AND NOT jane'. Note that for this mode, no column can be specified in input parameter column_names; GPUdb will search through all string columns of the table that have text search enabled. Also, the first character of a search term cannot be a wildcard (* or ?), and search terms cannot be any of the following: "a", "an", "and", "are", "as", "at", "be", "but", "by", "for", "if", "in", "into", "is", "it", "no", "not", "of", "on", "or", "such", "that", "the", "their", "then", "there", "these", "they", "this", "to", "was", "will", "with".

  Search query types:

  • Multiple search terms

    ex. perfect union - will match any record containing "perfect", "union", or both.

  • Exact phrases

    ex. "Perfect Union" - will only match the exact phrase "Perfect Union"

  • Boolean (NOT, AND, OR, parentheses. OR assumed if no operator specified)

    ex. justice AND tranquility - will match only those records containing both justice and tranquility

  • XOR (specified with -)

    ex. justice - peace - will match records containing "justice" or "peace", but not both

  • Zero or more char wildcard - (specified with *)

    ex, est*is* - will match any records containing a word that starts with "est" and ends with "sh", such as "establish", "establishable", and "establishment"

  • Exactly one char wildcard - (specified with ?)

    ex. est???is* - will only match strings that start with "est", followed by exactly three letters, followed by "is", followed by one more letter. This would only match "establish"

  • Fuzzy search (term~)

    ex. rear~ will match rear,fear,bear,read,etc.

  • Proximity - match two words within a specified distance of eachother

    ex. "Union Tranquility"~10 will match any record that has the words Union and Tranquility within 10 words of eachother

  • Range - inclusive [<term1> TO <term2>] and exclusive {<term1> TO <term2>}. Note: This is a string search, so numbers will be seen as a string of numeric characters, not as a number. Ex. 2 > 123

    ex. [100 TO 200] will find all strings between 100 and 200 inclusive. ex. {alpha to beta} will find all strings between alpha and beta, but not the words alpha or beta

  • escaping special characters - Special characters are escaped with a backslash(), special characters are: + - && || ! ( ) { } [ ] ^ " ~ * ? :

• equals: exact whole-string match (accelerated)

• contains: partial substring match (not accelerated). If the column is a string type (non-charN) and the number of records is too large, it will return 0.

• starts_with: strings that start with the given expression (not accelerated), If the column is a string type (non-charN) and the number of records is too large, it will return 0.

• regex: full regular expression search (not accelerated). If the column is a string type (non-charN) and the number of records is too large, it will return 0.

The options 'case_sensitive' can be used to modify the behavior for all modes except 'search'

Input Parameter Description

Name	Type	Description
table_name	str	Name of the table on which the filter operation will be performed. Must be a valid GPUdb table, collection or view.
view_name	str	If provided, then this will be the name of the view containing the results. Must not be an already existing collection, table or view. Default value is ''.
expression	str	The expression with which to filter the table.
mode	str	The string filtering mode to apply. See above for details. The allowed values are: search equals contains starts_with regex
column_names	list of str	List of columns on which to apply the filter. Ignored for 'search' mode.
options	dict of str	Optional parameters. Default value is an empty dict ( {} ). Supported Parameters (keys) Parameter Description case_sensitive If 'false' then string filtering will ignore case. Does not apply to 'search' mode. Default value is 'true'. The allowed values are: true false

Output Parameter Description

Name	Type	Description
count	long	The number of records that passed the string filter.