For newcomers who are new to PowerDesigner, if you use PowerDesigner to design the structure of the table, if you just simply design the mapping relationship of the data model to view it, then ther
Month: September 2021
SQLite – Group By timestamp value range
I spent a lot of time reading and still can’t find the best solution. I am designing an Android calorie counter application and I am using SQLite.
I have a table_logs table, in which There are 2 f
Specify which row is returned on SQLite Group
I encountered a tricky problem. I store all versions of all documents in a table. Each document has a unique id, and the version is stored as an integer. It will increment when there is a new versi
Learn mobile phone programming to learn about the SQLite database
SQLite is an embedded database, and its database is a file. Since SQLite itself is written in C and is small in size, it is often integrated into various applications, even in iOS and Android apps
How do we know the lock state of SQLite DB?
1) Is there a pragma or any way to understand the current lock state of sqlite db?
2) In addition, is there a way to know if other processes are using the database? About #1: No, because the an
RSQLite and read data into memory
I may have overlooked something, but when using the RSQLite package, can I still use the special string “:memory:” in the R script to speed up data retrieval? Yes, it can still use the special s
New with Recursive CTE clause with SQLite
SQLite 3.8.3 adds support for CTE. I tried some sample CTEs on this page and they work fine. However, after reading the documentation and trying to adjust some examples, I can’t Create a simple tes
Export PDM model and generate documentation using PowerDesigner reverse engineering
Original: Using PowerDesigner reverse engineering to export PDM models and generate documents
Recently, it is necessary to refactor and optimize old projects. Since the projects are all years
If there are two or more conditions, how to use the replace command in SQLite
I want to update a row if it exists in the table, otherwise insert it into SQLite in a single query. From the SQLite documentation I found that we can use the REPLACE command to achieve this.
SQLITE – PREPARED statement and in expression
I have a database where users can search for records containing a list of one or more items. I am using IN for searching, but I cannot use IN to process prepared statements. This This is what I tri