Revert "structure"

This reverts commit 6c12cfb9ee65bf5928357dc35da1433ca0878c49.
Revert "Revert "Revert "Revert "Create database""""

This reverts commit 203ab4c2839868b73aff3611a0195e8c928d4fb0.
Revert "Revert "Revert "Create database"""

This reverts commit 557fea4257776d07b5de905420d1c4e01dc1ff12.
Revert "Revert "Create database""

This reverts commit 83643312d6aed22f0494ad8d3355a859b4ee3801.
Revert "Test database"

This reverts commit 2fd23d6b2dabff5caf4c5d8db13e7a4b738fd333.