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我有这个sqlite查询大约11k记录的返回数据集。此查询中是否存在可以帮助提升性能的范围。由于增强select性能sqlite查询的性能
SELECT count(*) as count, easting,northing FROM tableName where site='K' AND is_deleted=0 AND easting !='' AND northing !='' AND easting !=0 AND northing !=0.
这里是从那里我将拉动记录的表结构:
CREATE TABLE "g_livcol" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
"accession_no" INTEGER NOT NULL ,
"isLive" VARCHAR(5),
"taxanomic_name" VARCHAR(50),
"genus_name" VARCHAR(50),
"taxanomic_species" VARCHAR(50),
taxanomic_species2 VARCHAR(50),
taxon_is_epithet VARCHAR(50),
taxanomic_cv VARCHAR(50),
sec_key INTEGER,
site VARCHAR(5),
location_key VARCHAR(20),
sub_location1 INTEGER,
sub_location2 INTEGER,
count_of_loc_key INTEGER,
accession_quantity INTEGER,
canopy INTEGER,
height INTEGER,
easting DOUBLE,
northing DOUBLE,
created_at DATETIME,
updated_at DATETIME,
is_deleted BOOL DEFAULT (0))
你如何比较东数和数字和字符串? – sagi
显示表结构,您拥有的任何索引以及[EXPLAIN QUERY PLAN](http://www.sqlite.org/eqp.html)的输出。 –
@CL。这是一个错误,它总是会变成小数。无论如何,这里是表结构 –