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https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
synced 2025-04-20 09:07:44 +03:00
b53c231ca6
This patch improves handling of NULLs in textual fields in ColumnStore. Previously empty strings were considered NULLs and it could be a problem if data scheme allows for empty strings. It was also one of major reasons of behavior difference between ColumnStore and other engines in MariaDB family. Also, this patch fixes some other bugs and incorrect behavior, for example, incorrect comparison for "column <= ''" which evaluates to constant True for all purposes before this patch.
51 lines
1.9 KiB
Plaintext
51 lines
1.9 KiB
Plaintext
#
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# Test Comparison Functions like COALESCE, LEAST, GREATEST, ISNULL
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# Author: Bharath, bharath.bokka@mariadb.com
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#
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-- source ../include/have_columnstore.inc
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--disable_warnings
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DROP DATABASE IF EXISTS mcs91_db;
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--enable_warnings
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CREATE DATABASE mcs91_db;
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USE mcs91_db;
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CREATE TABLE t1
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(
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t1_int INT,
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t1_decimal DECIMAL(5,2),
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t1_text TEXT,
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t1_char CHAR(1),
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t1_datetime DATETIME
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)ENGINE=Columnstore;
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INSERT INTO t1 VALUES(NULL, NULL, NULL, NULL, '0000-00-00');
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INSERT INTO t1 VALUES(123456, 111.11, repeat('a',10), 'a', '1111-11-11 11:11:11');
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INSERT INTO t1 VALUES(NULL, 222.22, '', 'b', '2222-12-22 22:22:22');
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SELECT *, COALESCE(t1_int, 'No Value') FROM t1 ORDER BY t1_int;
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SELECT *, COALESCE(t1_decimal, 'No Value') FROM t1 ORDER BY t1_int;
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SELECT *, COALESCE(t1_text, 'No Value') FROM t1 ORDER BY t1_int;
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SELECT *, COALESCE(t1_datetime, 'No Value') FROM t1 ORDER BY t1_int;
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SELECT t1_int, t1_decimal, COALESCE(t1_text, LEFT(t1_char,10)) FROM t1 ORDER BY t1_int;
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SELECT t1_int, LEAST(t1_int, t1_decimal) FROM t1 ORDER BY 1;
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SELECT t1_int, LEAST(t1_int, t1_decimal, t1_text) FROM t1 ORDER BY 1;
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SELECT t1_int, LEAST(t1_int, t1_decimal, t1_text, t1_datetime) FROM t1 ORDER BY 1;
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SELECT t1_int, GREATEST(t1_int, t1_decimal) FROM t1 ORDER BY 1;
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SELECT t1_int, GREATEST(t1_int, t1_decimal, t1_text) FROM t1 ORDER BY 1;
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SELECT t1_int, GREATEST(t1_int, t1_decimal, t1_text, t1_datetime) FROM t1 ORDER BY 1;
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SELECT t1_int, LEAST(IFNULL(t1_int, 0), IFNULL(t1_decimal, 0), IFNULL(t1_text, 'no value'), IFNULL(t1_datetime, '0')) least,
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GREATEST(IFNULL(t1_int, 0), IFNULL(t1_decimal, 0), IFNULL(t1_text, 0), IFNULL(t1_datetime, 0)) highest
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FROM t1 ORDER BY 2;
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SELECT * FROM t1 WHERE ISNULL(t1_int) ORDER BY t1_decimal;
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SELECT * FROM t1 WHERE ISNULL(t1_decimal) ORDER BY t1_decimal;
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SELECT * FROM t1 WHERE ISNULL(t1_text) ORDER BY t1_decimal;
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SELECT * FROM t1 WHERE ISNULL(t1_datetime) ORDER BY t1_decimal;
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# Clean UP
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DROP DATABASE mcs91_db;
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