SQLite locate
lazarus / 16-Databases

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koch · 2016-09-14 06:46

I have Lazarus 1.4.4 + ZeosLIB (ZeosDBO) 7.1.4
My project working with SQLite3 database and i need to store float
numbers with precision 6 digits after comma.

Sample script for creating table in database:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i CREATE
TABLE "test" (  id          INTEGER NOT NULL PRIMARY KEY
AUTOINCREMENT,    f           DECIMAL(9,6)); 
Fill table with one record:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
ZQuery1.SQL.Text:='select * from test;';with ZQuery1 dobegin  Open; 
Insert;  FieldByName('f').AsFloat:=1.333333;  Post;end; 
When I need to search record i do:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
ZQuery1.Locate('f', 1.333333, []) - return TRUE, it's
OkZQuery1.Locate('f', 1.33335, []) - return FALSE, it's
OkZQuery1.Locate('f', 1.333332, []) - return TRUE, it's
MISTAKE!!!!!ZQuery1.Locate('f', 1.333334, []) - return TRUE, it's
MISTAKE!!!!! 
I have same behaviour when field 'f' have type REAL, DOUBLE or FLOAT.
I have same behaviour with Lazarus 1.6 and(or) with ZeosLIB 7.2.1-rc

Question: How i can locate float values with precision 6 in sqlite
table?

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balazsszekely · 2016-09-14 06:57

Loop through the records, then use the CompareValue function from math
unit:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i begin 
zQuery.DisableControls;  try    zQuery.First;    while not zQuery.EOF
do    begin      CompareValue(....);      zQuery.Next;    end; 
finally    zQuery.EnableControls;  end;end;

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koch · 2016-09-14 07:05

All records scan is not rational... I will have many thousand records
in this table.
May be exists another methods?

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ttomas · 2016-09-14 10:23

Quote from: koch on September 14, 2016, 09:05:57 amAll records scan is
not rational...
Locate do the same! Do you see Locate code?