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Chapter 14 updates

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anthonydb 2021-08-28 14:52:13 -04:00
parent 55072cffbc
commit 0e77052926
1 changed files with 15 additions and 21 deletions
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36
Chapter_14/Chapter_14.sql
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@ -7,7 +7,7 @@
-- Commonly used string functions
-- Full list at https://www.postgresql.org/docs/current/static/functions-string.html
-- Full list at https://www.postgresql.org/docs/current/functions-string.html
-- Case formatting
SELECT upper('Neal7');
@ -39,7 +39,7 @@ SELECT replace('bat', 'b', 'c');
-- Any character one or more times
SELECT substring('The game starts at 7 p.m. on May 2, 2024.' from '.+');
-- One or two digits followed by a space and p.m.
-- One or two digits followed by a space and a.m. or p.m. in a noncapture group
SELECT substring('The game starts at 7 p.m. on May 2, 2024.' from '\d{1,2} (?:a.m.|p.m.)');
-- One or more word characters at the start
SELECT substring('The game starts at 7 p.m. on May 2, 2024.' from '^\w+');
@ -54,16 +54,6 @@ SELECT substring('The game starts at 7 p.m. on May 2, 2024.' from 'May \d, \d{4}
-- Listing 14-1: Using regular expressions in a WHERE clause
SELECT county_name
FROM us_counties_pop_est_2019
WHERE county_name ~* '(.+lade.+|.+lare.+)'
ORDER BY county_name;
SELECT county_name
FROM us_counties_pop_est_2019
WHERE county_name ~* '.+ash.+' AND county_name !~ 'Wash.+'
ORDER BY county_name;
SELECT county_name
FROM us_counties_pop_est_2019
WHERE county_name ~* '(lade|lare)'
@ -74,7 +64,7 @@ FROM us_counties_pop_est_2019
WHERE county_name ~* 'ash' AND county_name !~ 'Wash'
ORDER BY county_name;
-- Listing 14-2: Regular expression functions to replace and split
-- Listing 14-2: Regular expression functions to replace and split text
SELECT regexp_replace('05/12/2024', '\d{4}', '2023');
@ -125,14 +115,14 @@ ORDER BY crime_id;
-- Listing 14-8: Using regexp_match() to find the second date
-- Note that the result includes an unwanted hyphen
SELECT crime_id,
regexp_match(original_text, '-\d{1,2}\/\d{1,2}\/\d{1,2}')
regexp_match(original_text, '-\d{1,2}\/\d{1,2}\/\d{2}')
FROM crime_reports
ORDER BY crime_id;
-- Listing 14-9: Using a capture group to return only the date
-- Eliminates the hyphen
SELECT crime_id,
regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})')
regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})')
FROM crime_reports
ORDER BY crime_id;
@ -151,8 +141,8 @@ ORDER BY crime_id;
SELECT crime_id,
regexp_match(original_text, '\d{1,2}\/\d{1,2}\/\d{2}') AS date_1,
CASE WHEN EXISTS (SELECT regexp_matches(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})'))
THEN regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})')
CASE WHEN EXISTS (SELECT regexp_matches(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})'))
THEN regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})')
ELSE NULL
END AS date_2,
regexp_match(original_text, '\/\d{2}\n(\d{4})') AS hour_1,
@ -203,7 +193,7 @@ SET date_1 =
date_2 =
CASE
-- if there is no second date but there is a second hour
WHEN (SELECT regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})') IS NULL)
WHEN (SELECT regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})') IS NULL)
AND (SELECT regexp_match(original_text, '\/\d{2}\n\d{4}-(\d{4})') IS NOT NULL)
THEN
((regexp_match(original_text, '\d{1,2}\/\d{1,2}\/\d{2}'))[1]
@ -213,10 +203,10 @@ SET date_1 =
)::timestamptz
-- if there is both a second date and second hour
WHEN (SELECT regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})') IS NOT NULL)
WHEN (SELECT regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})') IS NOT NULL)
AND (SELECT regexp_match(original_text, '\/\d{2}\n\d{4}-(\d{4})') IS NOT NULL)
THEN
((regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{1,2})'))[1]
((regexp_match(original_text, '-(\d{1,2}\/\d{1,2}\/\d{2})'))[1]
|| ' ' ||
(regexp_match(original_text, '\/\d{2}\n\d{4}-(\d{4})'))[1]
||' US/Eastern'
@ -246,6 +236,10 @@ ORDER BY crime_id;
-- | (OR)
-- ! (NOT)
-- Note: You can view installed PostgreSQL search language configurations by running:
SELECT cfgname FROM pg_ts_config;
-- Listing 14-15: Converting text to tsvector data
SELECT to_tsvector('english', 'I am walking across the sitting room to sit with you.');
@ -331,7 +325,7 @@ WHERE search_speech_text @@
to_tsquery('english', 'transportation & !roads')
ORDER BY speech_date;
-- Listing 14-24: Find speeches where "defense" follows "military"
-- Listing 14-24: Finding speeches where "defense" follows "military"
SELECT president,
speech_date,