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我有這個sqlite查詢大約11k記錄的返回數據集。此查詢中是否存在可以幫助提升性能的範圍。由於增強select性能sqlite查詢的性能
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.
這裏是從那裏我將拉動記錄的表結構:
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))
你如何比較東數和數字和字符串? – sagi
顯示錶結構,您擁有的任何索引以及[EXPLAIN QUERY PLAN](http://www.sqlite.org/eqp.html)的輸出。 –
@CL。這是一個錯誤,它總是會變成小數。無論如何,這裏是表結構 –